Abel, Ulrich. “Asymptotic Approximation With Stancu Beta Operators”. Rev. Anal. Numér. Théor. Approx. 27, no. 1 (February 1, 1998): 5–13. Accessed May 1, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1998-vol27-no1-art2.