Bărbosu, Dan, and Ioana Zelina. “About Some Interpolation Formulas over Triangles”. Rev. Anal. Numér. Théor. Approx. 28, no. 2 (August 1, 1999): 117–123. Accessed April 14, 2025. https://ictp.acad.ro/jnaat/journal/article/view/1999-vol28-no2-art2.