Nowak, Grzegorz, and Aneta Sikorska-Nowak. “Some Approximation Properties of Modified Szasz-Mirakyan-Kantorovich Operators”. Rev. Anal. Numér. Théor. Approx., vol. 38, no. 1, Feb. 2009, pp. 73-82, https://doi.org/10.33993/jnaat381-903.