Păltănea, Radu. “ The Preservation of the Property of the Quasiconvexity of Higher Order by Bernstein’s Operators”. Rev. Anal. Numér. Théor. Approx. 25, no. 1 (August 1, 1996): 195–201. Accessed April 17, 2025. https://ictp.acad.ro/jnaat/journal/article/view/1996-vol25-nos1-2-art19.