A representation for the derivative of a meta-analytic function Sastry, M.S.K. (1979) Portugaliae mathematica
An initial and boundary value problem for nonlinear composite type systems of three equations. Begehr, H., Wen, G.C., Zhao, Z. (1991) Mathematica Pannonica
An integral formula for the derivatives of solutions of certain elliptic systems H. Renelt (1991) Annales Polonici Mathematici
Approximation von Nichtanalytischen Funktionen Durch Eine P-polyanalytische Funktion Miloš Čanak (1992) Publications de l'Institut Mathématique