Roşca, Daniela. “Bidimensional Interpolation Operators of Finite Element Type and Degree of Exactness Two”. Rev. Anal. Numér. Théor. Approx. 34, no. 2 (August 1, 2005): 195–205. Accessed November 24, 2024. https://ictp.acad.ro/jnaat/journal/article/view/2005-vol34-no2-art8.