Broken Hyperlinks
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AKS Primality Test: (2007-12-13) Indian Institute of Technology. "PRIMES is in P." http://www.cse.iitk.ac.in/news/primality.html
Apéry's Constant: (2025-12-19) Plouffe, S. "Table of Current Records for the Computation of Constants." http://pi.lacim.uqam.ca/eng/records_en.html
Arbelos: (2005-07-22) Woo, P. "The Arbelos." http://www-students.biola.edu/~woopy/math/arbelos.htm
B-Line: (2003-02-25) Todd, A. "Bisecting a Triangle." http://www.math.colostate.edu/~todd/triangle.html
Balaban 10-Cage: (2026-05-04) Royle, G. "Cubic Cages." http://school.maths.uwa.edu.au/~gordon/remote/cages/
Balaban 11-Cage: (2026-05-04) Royle, G. "Cubic Cages." http://school.maths.uwa.edu.au/~gordon/remote/cages/
Barth Sextic: (2003-02-26) Dominici, P. "Flight Through Barth's Sextic." http://www.mi.uni-erlangen.de/~bauerth/flight/
Bernoulli Number: (2025-12-19) Plouffe, S. "Table of Current Records for the Computation of Constants." http://pi.lacim.uqam.ca/eng/records_en.html
Bernoulli Number: (2025-12-19) Plouffe, S. "The 
th Bernoulli Number." May 21, 2002. http://www.lacim.uqam.ca/~plouffe/ber500000.txt
Biggs-Smith Graph: (2026-05-04) Royle, G. "F102A." http://www.csse.uwa.edu.au/~gordon/foster/F102A.html
Biggs-Smith Graph: (2026-05-04) Royle, G. "Cubic Symmetric Graphs (The Foster Census): Distance-Regular Graphs." http://school.maths.uwa.edu.au/~gordon/remote/foster/#drgs
Bordism: (2003-02-25) Budney, R. "The Bordism Project." http://www.math.cornell.edu/~rybu/bordism/bordism.html
Boy Surface: (2000-07-09) Wang, P. "Renderings." http://www.ugcs.caltech.edu/~peterw/portfolio/renderings/
Brier Number: (2008-08-09) McLean, J. "Brier Numbers." http://www.glasgowg43.freeserve.co.uk/brier2.htm
Cage Graph: (2026-05-04) Royle, G. "Cubic Cages." http://school.maths.uwa.edu.au/~gordon/remote/cages/
Cage Graph: (2026-05-04) Royle, G. "Cages of Higher Valency." http://school.maths.uwa.edu.au/~gordon/remote/cages/allcages.html
Catalan's Constant: (2025-12-19) Plouffe, S. "Table of Current Records for the Computation of Constants." http://pi.lacim.uqam.ca/eng/records_en.html
Cayley Graph: (2026-05-04) Royle, G. "Cayley Graphs." http://school.maths.uwa.edu.au/~gordon/remote/cayley/
Cayley Graph: (2026-05-04) Royle, G. "Transitive Graphs." http://school.maths.uwa.edu.au/~gordon/trans/
Circle Packing: (2007-11-01) Boll, D. "Packing Results." http://www.frii.com/~dboll/packing.html
Circle Packing: (2003-02-25) Nurmela, K. J. and Östergård, P. R. J. packings/square/. http://www.tcs.hut.fi/packings/square/
Class 1 Graph: (2026-05-04) Royle, G. "Class 2 Graphs." http://school.maths.uwa.edu.au/~gordon/remote/graphs/#class2
Class 2 Graph: (2026-05-04) Royle, G. "Class 2 Graphs." http://school.maths.uwa.edu.au/~gordon/remote/graphs/#class2
Combinatorial Geometry: (2026-05-08) Friedman, E. "Erich's Combinatorial Geometry Page." http://www.stetson.edu/~efriedma/comb.html
Combinatorics: (1999-12-06) Coolsaet, K. "Index of Combinatorial Objects." http://gonzo.hogent.be/~kc/ico/
Complexity Theory: (2003-03-12) Goetz, P. "Phil Goetz's Complexity Dictionary." http://www.cs.buffalo.edu/~goetz/dict.html
Constant: (2025-12-19) Plouffe, S. "Plouffe's Inverter: Table of Current Records for the Computation of Constants." http://pi.lacim.uqam.ca/eng/records_en.html
Coxeter Graph: (2026-05-04) Royle, G. "F028A." http://www.csse.uwa.edu.au/~gordon/foster/F028A.html
Coxeter's Loxodromic Sequence of Tangent Circles: (2006-02-14) Coxeter, D. "Coxeter on 'Firmament.' " http://www.bangor.ac.uk/SculMath/image/donald.htm
Cube: (2011-04-26) Hidekazu, T. "Research on a Cube." http://www.biwako.ne.jp/~hidekazu/materials/cubee.htm
Cubic Graph: (2026-05-04) Royle, G. "All Cubic Graphs." http://people.csse.uwa.edu.au/gordon/remote/cubics/
Cubic Symmetric Graph: (2026-05-04) Royle, G. "Cubic Symmetric Graphs (The Foster Census)." http://school.maths.uwa.edu.au/~gordon/remote/foster/#census
Cubic Symmetric Graph: (2026-05-04) Royle, G. "Browse the Graphs." http://school.maths.uwa.edu.au/~gordon/remote/foster/tables.html
Cubical Graph: (2026-05-04) Royle, G. "F008A." http://www.csse.uwa.edu.au/~gordon/foster/F008A.html
Cyclide: (1998-10-08) Bierschneider-Jakobs, A. "Cyclides." http://www.mi.uni-erlangen.de/~biersch/cyclides.html
Cycloid: (2003-02-25) Muterspaugh, J.; Driver, T.; and Dick, J. E. "The Cycloid and Tautochronism." http://php.indiana.edu/~jedick/project/intro.html
Desargues Graph: (2026-05-04) Royle, G. "F020B." http://www.csse.uwa.edu.au/~gordon/foster/F020B.html
Desargues Graph: (2026-05-04) Royle, G. "Cubic Symmetric Graphs (The Foster Census): Distance-Regular Graphs." http://school.maths.uwa.edu.au/~gordon/remote/foster/#drgs
Diophantine Equation--6th Powers: (2003-02-25) Resta, G. "New Results on Equal Sums of Sixth Powers." Instituto di Matematica Computazionale, Pisa, Italy. April 1999. http://www.chez.com/powersum/Tr-b4-08.zip
Distance-Regular Graph: (2026-05-04) Royle, G. "Cubic Symmetric Graphs (The Foster Census): Distance-Regular Graphs." http://school.maths.uwa.edu.au/~gordon/remote/foster/#drgs
Dodecahedral Graph: (2026-05-04) Royle, G. "F020A." http://www.csse.uwa.edu.au/~gordon/foster/F020A.html
Domino: (2003-02-25) Lei, A. "Domino." http://www.cs.ust.hk/~philipl/omino/domino.html
Double Bubble: (2025-02-06) Sullivan, J. M. "Double Bubble Images." http://torus.math.uiuc.edu/jms/Images/double/
e: (2025-12-19) Plouffe, S. "Table of Current Records for the Computation of Constants." http://pi.lacim.uqam.ca/eng/records_en.html
Egyptian Fraction: (1998-02-14) Gardner, M. "Babylonian and Egyptian Mathematics, an Egyptian Historical Gap, Installments 1-3." http://www.teleport.com/~ddonahue/phresour.html
Euler-Mascheroni Constant: (2025-12-19) Plouffe, S. "Table of Current Records for the Computation of Constants." http://pi.lacim.uqam.ca/eng/records_en.html
Factorial Prime: (2026-05-04) Caldwell, C. K. "Prime Links++." http://primes.utm.edu/links/theory/special_forms/near_products/factorial
Fibonacci Number: (2003-02-25) Leyland, P. ftp://sable.ox.ac.uk/pub/math/factors/fibonacci.Z
Finite Group: (2026-05-04) Royle, G. "Numbers of Small Groups." http://school.maths.uwa.edu.au/~gordon/remote/cubcay/
Flexagon: (2000-07-09) Conrad, A. S. and Harline, D. K. "Flexagons." TR 62-11, May 1962. http://delta.cs.cinvestav.mx/~mcintosh/newweb/new.html
Flower of Life: (2003-02-25) Wein, J. "La Fleur de Vie." http://www2.cruzio.com/~flower/fleur.htm
Foster Graph: (2026-05-04) Royle, G. "F090A." http://www.csse.uwa.edu.au/~gordon/foster/F090A.html
Foster Graph: (2026-05-04) Royle, G. "Cubic Symmetric Graphs (The Foster Census): Distance-Regular Graphs." http://school.maths.uwa.edu.au/~gordon/remote/foster/#drgs
Fullerene: (2026-05-04) Royle, G. "Fullerenes." http://school.maths.uwa.edu.au/~gordon/remote/fullerenes/
Game of Life: (1999-11-15) McIntosh, H. V. "Life." http://www.cs.cinvestav.mx/mcintosh/oldweb/life.html
Generalized Polygon: (2026-05-04) Royle, G. "Cubic Cages." http://school.maths.uwa.edu.au/~gordon/remote/cages/
Goblet Illusion: (1998-02-01) "Reversible Goblet." http://www.nari.ee.ethz.ch/nari_lectures/bildkom/Studenten_Projekte/Sommer96/Projekt5/sub1/goblet.html
Goblet Illusion: (1999-12-06) What's Up with Kids Magazine. "Reversible Goblet." http://wuwk.spurtek.com/COI_reversible_goblet.htm
Goldbach Conjecture: (2026-05-04) Caldwell, C. K. "Prime Links++." http://primes.utm.edu/links/theory/conjectures/Goldbach/
Golden Ratio Conjugate: (2025-02-27) Knott, R. "Fibonacci Numbers and the Golden Section." http://www.mcs.surrey.ac.uk/Personal/R.Knott/Fibonacci/
Haberdasher's Problem: (1999-12-06) Chuan, J. C. "Geometric Construction." http://www.math.ntnu.edu.tw/gc/chuan/gc.html
Heawood Graph: (2026-05-04) Royle, G. "Cubic Cages." http://school.maths.uwa.edu.au/~gordon/remote/cages/
Heawood Graph: (2026-05-04) Royle, G. "F014A." http://www.csse.uwa.edu.au/~gordon/foster/F014A.html
Heilbronn Triangle Problem: (2026-05-08) Friedman, E. "The Heilbronn Problem for Circles." http://www.stetson.edu/~efriedma/heilcirc/
Heptadecagon: (2000-07-09) Wang, P. "The Regular Heptadecagon." http://www.ugcs.caltech.edu/~peterw/studies/17gon/
Hexiamond: (2000-07-09) Paulhus, M. "The Hexiamond Home Page." http://www.math.ucalgary.ca/~paulhusm/hexiamond1/
Hilbert Curve: (2003-03-12) Goetz, P. "Phil Goetz's Complexity Dictionary." http://www.cs.buffalo.edu/~goetz/dict.html
Hyperbolic Plane: (2026-05-01) Taimina, D. "Mysteries of the Hyperbolic Plane." Carleton College News, May 18, 2006. http://apps.carleton.edu/news/?content=content&module=&id=193307
Icosahedron Stellations: (2000-07-09) Wang, P. "Polyhedra." http://www.ugcs.caltech.edu/~peterw/portfolio/polyhedra/
Josephus Problem: (2005-09-13) Smith, H. J. "Josephus Permutation Problems." http://www.geocities.com/hjsmithh/Josephus.html
Khinchin's Constant Digits: (2025-12-19) Plouffe, S. "Table of Current Records for the Computation of Constants." http://pi.lacim.uqam.ca/eng/records_en.html
Knight Graph: (2012-12-15) Jelliss, G. "Knight's Tour Notes." http://www.ktn.freeuk.com/
Knight Graph: (2012-12-15) Jelliss, G. "Chronology of Knight's Tours." http://www.ktn.freeuk.com/cc.htm
Knot: (1997-08-18) Zia. "Zia Knotting." http://204.30.30.10/hac/knots/
Kolmogorov Complexity: (2003-03-12) Goetz, P. "Phil Goetz's Complexity Dictionary." http://www.cs.buffalo.edu/~goetz/dict.html
Lucas Number: (2003-02-25) Leyland, P. ftp://sable.ox.ac.uk/pub/math/factors/lucas.Z
Machin-Like Formulas: (2009-03-10) Williams, R. "Arctangent Formulas for Pi." http://www.cacr.caltech.edu/~roy/upi/pi.formulas.html
Magic Circles: (1999-12-06) Hung, K. M. "Magic Circle." http://home.hkstar.com/~hkm88630/magiccl.html
Magic Cube: (2003-02-25) Lei, A. "Magic Cube and Hypercube." http://www.cs.ust.hk/~philipl/magic/mcube2.html
Magic Square: (2003-02-25) Lei, A. "Magic Square, Cube, Hypercube." http://www.cs.ust.hk/~philipl/magic/
Magic Tour: (2012-12-15) Jelliss, G. "Knight's Tour Notes." http://home.freeuk.net/ktn/
Magic Tour: (2012-12-15) Jelliss, G. "General Theory of Magic Knight's Tours." http://home.freeuk.net/ktn/mg.htm
Matchstick Graph: (2022-01-03) Timm, M. "Diskrete Mathematik." http://www.mathematik.tu-bs.de/dm/
McGee Graph: (2026-05-04) Royle, G. "Cubic Cages." http://school.maths.uwa.edu.au/~gordon/remote/cages/
McLaughlin Graph: (2026-05-04) Royle, G. "The McLaughlin Graph." http://www.csse.uwa.edu.au/~gordon/constructions/mclaughlin
Minimal Enclosing Circle: (2025-03-31) Elisoff, J. and Unger, R. "Minimal Enclosing Circle Problem." Oct. 1998. http://www.cs.mcgill.ca/~cs507/projects/1998/jacob/problem.html
Möbius Strip: (1997-04-16) Dickau, R. "Spinning Möbius Strip Movie." http://mathforum.org/advanced/robertd/moebius.html
Möbius Strip: (2000-07-09) Wang, P. "Renderings." http://www.ugcs.caltech.edu/~peterw/portfolio/renderings/
Moore Graph: (2026-05-04) Royle, G. "Cages of Higher Valency." http://www.csse.uwa.edu.au/~gordon/cages/allcages.html
Multiperfect Number: (1996-10-07) Perrier, J.-Y. "The Multi-Perfect Numbers." http://diwww.epfl.ch/~perrier/Multiparfaits.html
Narcissistic Number: (2000-07-09) Corning, T. "Exponential Digital Invariants." http://members.aol.com/tec153/Edi4web/Edi.html
Nevanlinna Prize: (2008-05-06) International Congress of Mathematics. "Rolf Nevanlinna Prize." http://www.icm2002.org.cn/general/prize/nevanlinna.htm International Mathematical Union. "Fields Medals and Rolf Nevanlinna Prize." http://www.mathunion.org/medals/.
Noncayley Graph: (2026-05-04) Royle, G. "Transitive Graphs." http://school.maths.uwa.edu.au/~gordon/trans/
Nonhamiltonian Graph: (2026-05-04) Royle, G. "Cubic Symmetric Graphs (The Foster Census): Hamiltonian Cycles." http://school.maths.uwa.edu.au/~gordon/remote/foster/#hamilton
Nonhamiltonian Vertex-Transitive Graph: (2026-05-04) Royle, G. "Transitive Graphs." http://school.maths.uwa.edu.au/~gordon/trans/
Oloid: (2003-02-26) Capocasa, C. "Oloid." http://www.blackpoint.net/capocssa/oloid.html
Pappus Graph: (2026-05-04) Royle, G. "F018A." http://www.csse.uwa.edu.au/~gordon/foster/F018A.html
Pappus Graph: (2026-05-04) Royle, G. "Cubic Symmetric Graphs (The Foster Census): Distance-Regular Graphs." http://school.maths.uwa.edu.au/~gordon/remote/foster/#drgs
Pentomino: (2003-02-26) Lei, A. "Pentominoes." http://www.cs.ust.hk/~philipl/omino/pento.html
Perfect Rectangle: (2025-12-15) Wolf, T. "The 
Puzzle." http://home.tiscalinet.ch/t_wolf/tw/misc/squares.html
Perfect Square Dissection: (2025-12-15) Wolf, T. "The 
Puzzle." http://home.tiscalinet.ch/t_wolf/tw/misc/squares.html
Petersen Graph: (2026-05-04) Royle, G. "F010A." http://www.csse.uwa.edu.au/~gordon/foster/F010A.html
Pi: (2025-12-19) Plouffe, S. "Table of Current Records for the Computation of Constants." http://pi.lacim.uqam.ca/eng/records_en.html
Pi: (2003-02-25) Plouffe, S. "1 Billion Digits of Pi." http://pi.lacim.uqam.ca/eng/
Pi: (2025-12-19) Plouffe, S. "A Few Approximations of Pi." http://pi.lacim.uqam.ca/eng/approximations_en.html
Pi: (2025-12-19) Plouffe, S. "PiHex: A Distributed Effort to Calculate Pi." http://www.cecm.sfu.ca/projects/pihex/
Pi: (2025-12-15) Plouffe, S. "The 
Page." http://www.cecm.sfu.ca/pi/
Pi: (2025-12-19) Plouffe, S. "Table of Computation of Pi from 2000 BC to Now." http://oldweb.cecm.sfu.ca/projects/ISC/Pihistory.html
Pi Digits: (2003-02-25) Kanada, Y. "Our Latest Record." Sep. 20, 1999. ftp://www.cc.u-tokyo.ac.jp/README.our_latest_record
Pi Digits: (2025-12-19) Plouffe, S. "Table of Current Records for the Computation of Constants." http://pi.lacim.uqam.ca/eng/records_en.html
Poggendorff Illusion: (2003-02-25) IllusionWorks. "Poggendorf [sic]." http://www.illusionworks.com/html/poggendorf.html
Polyomino: (2003-02-25) Lei, A. "Bigger Polyominoes." http://www.cs.ust.hk/~philipl/omino/bigpolyo.html
Polyomino: (2003-02-25) Lei, A. "Polyominoes." http://www.cs.ust.hk/~philipl/omino/omino.html
Primorial Prime: (2003-02-25) Leyland, P. ftp://sable.ox.ac.uk/pub/math/factors/primorial-.Z
Prisoner's Dilemma: (2003-03-12) Goetz, P. "Phil Goetz's Complexity Dictionary." http://www.cs.buffalo.edu/~goetz/dict.html
Proth Prime: (2026-05-04) Caldwell, C. K. "Yves Gallot's Proth.exe: An implementation of Proth's Theorem for Windows." http://www.utm.edu/research/primes/programs/gallot/
Pseudoprime: (2026-05-04) Caldwell, C. K. "Prime Links++." http://primes.utm.edu/links/theory/finding_and_proving/probable_primality/
Quadric: (2003-02-25) Takahashi, H. "Quadrica Page." http://www2.kawase-h.ed.jp/Teachers/~Takahashi/Quadrica.html
Qubic: (2005-08-06) Allis, L. V. "Qubic." http://www.cs.vu.nl/~victor/qubic.html
Real Number: (2003-02-25) Shamos, M. I. A Catalog of Real Numbers. In preparation? http://www.ecom.cmu.edu/people/faculty/mshamos/resshort.htm
Riemann Hypothesis: (2026-05-04) Caldwell, C. K. "Prime Links++." http://primes.utm.edu/links/theory/conjectures/Riemann/
Roman Surface: (2000-07-09) Wang, P. "Renderings." http://www.ugcs.caltech.edu/~peterw/portfolio/renderings/
RSA Number: (2003-02-25) Leyland, P. ftp://sable.ox.ac.uk/pub/math/rsa129
Self-Complementary Graph: (2026-05-04) Royle, G. "Self-Complementary Graphs." http://school.maths.uwa.edu.au/~gordon/remote/selfcomp/
Semimagic Square: (2012-12-15) Jelliss, G. "Knight's Tour Notes." http://home.freeuk.net/ktn/
Semimagic Square: (2012-12-15) Jelliss, G. "General Theory of Magic Knight's Tours." http://home.freeuk.net/ktn/mg.htm
Sierpiński Sieve: (2000-07-09) Wang, P. "Renderings." http://www.ugcs.caltech.edu/~peterw/portfolio/renderings/
Singular Integral: (2004-09-28) Paulino, G. H. "Singular Integrals." Fall 2001. http://cee.ce.uiuc.edu/paulino/BEM/handouts/sing.pdf
Snark: (2026-05-04) Royle, G. "Snarks." http://people.csse.uwa.edu.au/gordon/remote/cubics/#snarks
Sphere Packing: (2026-05-08) Friedman, E. "Spheres in Cubes." http://www.stetson.edu/~efriedma/sphincub/
Spherical Code: (2011-03-18) Friedman, E. "Points on a Sphere." http://www.stetson.edu/~efriedma/ptsphere/
Spikey: (2018-12-07) Bell, R. "Spiky: The Temple of Archimedes." http://www.zomadic.com/spiky/
Square Pyramidal Number: (2025-12-15) Wolf, T. "The 
Puzzle." http://home.tiscalinet.ch/t_wolf/tw/misc/squares.html
Steinbach Screw: (2000-07-09) Naylor, B. "Steinbach Screw 1." http://www.garlic.com/~bnaylor/raytrace/rtstein1.html
Steinbach Screw: (2000-07-09) Wang, P. "Renderings." http://www.ugcs.caltech.edu/~peterw/portfolio/renderings/
Strongly Regular Graph: (2026-05-04) Royle, G. "Strongly Regular Graphs." http://school.maths.uwa.edu.au/~gordon/remote/srgs/
Sudoku: (2026-05-04) Royle, G. "Minimum Sudoku." http://www.csse.uwa.edu.au/~gordon/sudokumin.php
Sudoku: (2026-05-04) Royle, G. "Sudoku Patterns." http://www.csse.uwa.edu.au/~gordon/sudokupat.php
Surface: (2003-02-25) Endraß, S. "Home Page of S. Endraß." http://www.mathematik.uni-mainz.de/~endrass/
Tautochrone Problem: (2003-02-25) Muterspaugh, J.; Driver, T.; and Dick, J. E. "The Cycloid and Tautochronism." http://php.indiana.edu/~jedick/project/intro.html
Tautochrone Problem: (2003-02-25) Muterspaugh, J.; Driver, T.; and Dick, J. E. "P221 Tautochrone Problem." http://php.indiana.edu/~jedick/project/project.html
Templar Magic Square: (1998-11-12) Heietala, H. "The Templar Magic Square." http://www.trantex.fi/staff/heikkih/knights/pubsator.htm
Ternary Diagram: (2025-12-15) Vaughn, W. "Ternary Plots." 2010. http://wvaughan.org/ternaryplots.html
Tetrahedral Graph: (2026-05-04) Royle, G. "F004A." http://www.csse.uwa.edu.au/~gordon/foster/F004A.html
Tetrahedron 5-Compound: (2000-07-09) Wang, P. "Renderings." http://www.ugcs.caltech.edu/~peterw/portfolio/renderings/
Tit-for-Tat: (2003-03-12) Goetz, P. "Phil Goetz's Complexity Dictionary." http://www.cs.buffalo.edu/~goetz/dict.html
Tree: (2026-05-04) Royle, G. "Trees On Up to 16 [sic] Vertices." http://school.maths.uwa.edu.au/~gordon/remote/graphs/#trees
Triomino: (2003-02-25) Lei, A. "Tromino." http://www.cs.ust.hk/~philipl/omino/tromino.html
Tutte 8-Cage: (2022-10-31) Royle, G. "F030A." http://www.csse.uwa.edu.au/~gordon/foster/F030A.html
Tutte 8-Cage: (2022-10-31) Royle, G. "Cubic Cages." http://school.maths.uwa.edu.au/~gordon/remote/cages/
Tutte 12-Cage: (2026-05-04) Royle, G. "Cubic Cages." http://school.maths.uwa.edu.au/~gordon/remote/cages/
Tutte Graph: (2026-05-04) Royle, G. "Cubic Cages." http://school.maths.uwa.edu.au/~gordon/remote/cages/
Utility Graph: (2026-05-04) Royle, G. "F006A." http://www.csse.uwa.edu.au/~gordon/foster/F006A.html
Vampire Number: (2008-12-25) Schneider, W. "Vampire Numbers." http://wschnei.de/digit-related-numbers/vampire.html Sloane, N. J. A. Sequences A014575, A048933, A048934, A048935, A048936, A048937, A048938, and A048939 in "The On-Line Encyclopedia of Integer Sequences."
Vertex-Transitive Graph: (2026-05-04) Royle, G. "Cubic Symmetric Graphs (The Foster Census): Hamiltonian Cycles." http://school.maths.uwa.edu.au/~gordon/remote/foster/#hamilton
Vertex-Transitive Graph: (2026-05-04) Royle, G. "Transitive Graphs." http://school.maths.uwa.edu.au/~gordon/trans/
Vizing's Theorem: (2026-05-04) Royle, G. "Class 2 Graphs." http://school.maths.uwa.edu.au/~gordon/remote/graphs/#class2
Whitney Umbrella: (2000-07-09) Geometry Center. "Whitney's Umbrella." http://www.geom.umn.edu/zoo/features/whitney/
Wilf-Zeilberger Pair: (2025-12-19) Wedeniwski, S. "
Digits of Zeta(3)." http://pi.lacim.uqam.ca/eng/records_en.html
Zipf's Law: (2003-03-12) Goetz, P. "Phil Goetz's Complexity Dictionary." http://www.cs.buffalo.edu/~goetz/dict.html
Zöllner's Illusion: (2003-02-25) IllusionWorks. "Poggendorf [sic]." http://www.illusionworks.com/html/poggendorf.html
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