Ivan, M., and I. Rașa. “A Sequence of Positive Linear Operators”. Rev. Anal. Numér. Théor. Approx. 24, no. 1 (August 1, 1995): 159–164. Accessed April 26, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1995-vol24-nos1-2-art16.