Braess, Dietrich On the numer of best approximations in certain non-linear families of functions. (English) Zbl 0304.41014 Aequationes Math. 12, 184-199 (1975). MSC: 41A50 × Cite Format Result Cite Review PDF Full Text: DOI EuDML
Dunham, Charles B. Approximation with respect to sums of Chebyshev norms. (English) Zbl 0251.41009 Aequationes Math. 8, 267-270 (1972). MSC: 41A50 × Cite Format Result Cite Review PDF Full Text: DOI EuDML