[1] A.M. Acu, T. Acar, C.V. Muraru and V.A. Radu, Some approximation properties by a class of bivariate operators, Math. Meth. Appl. Sci. 42 (2019), 5551–5565.
[2] O. Agratini, Bivariate positive operators in polynomial weighted spaces, Abstr. Appl. Anal. 2013 (2013), 8.
[3] P.N. Agrawal and M. Goyal, Generalized Baskakov Kantorovich operators, Filomat 31(19) (2017) 6131–6151.
[4] P.N. Agrawal, V. Gupta, and A. Sathish Kumar, Generalized Baskakov-Durrmeyer type operators, Rend. Circ. Mat. Palermo 63 (2014), no. 2, 193–209.
[5] F. Altomare and M. Campiti, Korovkin-Type Approximation Theory and its Applications, de Gruyter Studies in Mathematics, 17. Walter de Grutyer and Co., Berlin 1994.
[6] F. Altomare and M. Cappelletti Montano and V. Leonessa, On a generalization of Szasz-Mirakjan-Kantorovich operators, Results Math. 63 (2013), no. 3-4, 837–863.
[7] G.A. Anastassiou and S. Gal, Approximation Theory. Moduli of Continuity and Global Smoothness Preservation, Birkhauser, Boston, 2000.
[8] D. Barbosu, Some generalized bivariate Bernstein operators, Math. Notes (Miskolc) 1 (2000), no. 1, 3–10.
[9] P.L. Butzer and H. Berens, Semi-groups of Operators and Approximation, Springer, New York, 1967.
[10] O. Dogru and V. Gupta, Korovkin-type approximation properties of bivariate q−Meyer-Konig and Zeller operators, Calcolo 43 (2006), no. 1, 51–63.
[11] A. Eren,cin, Durrmeyer type modification of generalized Baskakov operators, Appl. Math. Comput. 218 (2011), no. 8, 4384–4390.
[12] B. Firlej and L. Rempulska, Approximation of functions of several variables by some operators of the Szasz-Mirakjan type, Fasc. math. 27 (1997) 15–27.
[13] M. Gurdek, L. Rempulska and M. Skorupka, The Baskakov operators for functions of two variables, Collect. Math. 50 (1999), no. 3, 289–302.
[14] A. Kajla and M. Goyal, Modified Bernstein-Kantorovich operators for functions of one and two variables, Rend. Circ. Mat. di Palermo II 67 (2018), no. 2, 379–395.
[15] V. Mihesan, Uniform approximation with positive linear operators generated by generalized Baskakov method, Automat. Comput. Appl. Math. 7 (1998), no. 1, 34–37.
[16] M. Nasiruzzaman, Approximation properties by Szasz-Mirakjan operators to bivariate functions via Dunkl analogue, Iran. J. Sci. Technol. Trans. A, Sci. 45 (2021), 259–269.
[17] F. Ozger, Weighted statistical approximation properties of univariate and bivariate λ-Kantorovich operators. Filomat 33 (2019), no. 11, 3473–3486.
[18] L. Rempulska and M. Skorupka, On convergence of first derivatives of certain Szasz-Mirakyan type operators, Rend. Mat. Appl. 19 (1999), no. 2, 269–279.
[19] M. Skorupka, Approximation of functions of two variables by some linear positive operators, Matematiche (Catania) 50 (1995), no. 2, 323–336.
[20] DD. Stancu, A new class of uniform approximating polynomial operators in two and several variables. G. Alexits, S. B. Stechkin (eds.): Proc. Conf. Consecutive Theory Functions, Budapest: Akad. Kiado, 1972, pp. 443–455.
[21] A. Wafi and S. Khatoon, Approximation by generalized Baskakov operators for functions of one and two variables in exponential and polynomial weight spaces, Thai. J. Math. 2 (2004) 53–66.
[22] A. Wafi and S. Khatoon, Convergence and Voronovskaja-type theorems for derivatives of generalized Baskakov operators, Cent. Eur. J. Math. 6 (2008), no. 2, 325–334.
[23] R. Yadav, R. Meher and V.N. Mishra, Results on bivariate Szasz-Mirakjan type operators in polynomial weight spaces, Math. Eng. Sci. Aerosp. 11 (2020), no. 4, 939–957.
[24] R. Yadav, R. Meher and V.N. Mishra, Quantitative estimations of bivariate summation-integral-type operators, Math. Meth. Appl. Sci. 42 (2019), 7172–7191.
[25] G. You and P. Xaun, Weighted approximation by multidimensional Baskakov operators, J. Math. Res. Expos. 20 (2000), no. 1, 43–50.