1. Regular curve-families filling the plane, I;Kaplan, Wilfred;Duke Math. J.,1940
2. Regular curve-families filling the plane, II;Kaplan, Wilfred;Duke Math. J.,1941
3. The structure of a curve-family on a surface in the neighborhood of an isolated singularity;Kaplan, Wilfred;Amer. J. Math.,1942
4. Differentiability of regular curve families on the sphere;Kaplan, Wilfred,1941
5. R. Nevanlinna, Eindeutige analytische Funktionen, Berlin, 1936.