Agratini, Octavian. “Stancu Modified Operators Revisited”. Rev. Anal. Numér. Théor. Approx. 31, no. 1 (February 1, 2002): 9–16. Accessed April 15, 2025. https://ictp.acad.ro/jnaat/journal/article/view/2002-vol31-no1-art2.