Let 
 be curves such that 
 and 
,
 and suppose that 
 and 
 have holomorphic extensions 
 such that 
 and 
 also for 
. Fix 
. Then the Björling curve, defined
 by
is a minimal curve (Gray 1997, p. 762).
 
	    
	
    
Let 
 be curves such that 
 and 
,
 and suppose that 
 and 
 have holomorphic extensions 
 such that 
 and 
 also for 
. Fix 
. Then the Björling curve, defined
 by
is a minimal curve (Gray 1997, p. 762).
Weisstein, Eric W. "Björling Curve." From MathWorld--A Wolfram Resource. https://mathworld.wolfram.com/BjoerlingCurve.html