Some remarks on the existence and uniqueness of solutions of the hyperbolic equation ∂²z/(∂x∂y)=f(x,y,x,∂z/∂x,∂z/∂y)
Tom 15 / 1956
Studia Mathematica 15 (1956), 201-215
DOI: 10.4064/sm-15-2-201-215