Scherer, Karl. “Best Approximation by Chebyshevian Splines and Generalized Lipschitz Spaces”. Anal. Numér. Théor. Approx. 5, no. 1 (February 1, 1976): 87–95. Accessed May 8, 2024. https://ictp.acad.ro/jnaat/journal/article/view/1976-vol5-no1-art9.