Delvos, F. J., and H. Posdorf. “A Boolean Method in Bivariate Interpolation”. Anal. Numér. Théor. Approx. 9, no. 1 (February 1, 1980): 35–45. Accessed April 11, 2025. https://ictp.acad.ro/jnaat/journal/article/view/1980-vol9-no1-art5.