1. On class of linear positive bivariate operators of King, Studia Univ. “Babeş–Bolyai”;Agratini;Mathematica,2006
2. Korovkin-Type Approximation Theory and its Applications;Altomare,1994
3. Voronovskaya type asymptotic formula for Lupaş–Durrmeyer operators, Revista De La;Deo;Unio˘n Mathematica Argentina,2007
4. Approximation in boundless interval and order of approximation;İzgi;Kastamonu Eğ itim dergisi,2003
5. Order of approximation of functions of two variables by new type Gamma operators;İzgi;General Mathematics,2009