Wulbert, Daniel Uniqueness and differential characterization of approximations from manifolds of functions. (English) Zbl 0227.41009 Am. J. Math. 93, 350-366 (1971). Page: −5 −4 −3 −2 −1 ±0 +1 +2 +3 +4 +5 Show Scanned Page Cited in 45 Documents MSC: 41A52 Uniqueness of best approximation 41A50 Best approximation, Chebyshev systems PDF BibTeX XML Cite \textit{D. Wulbert}, Am. J. Math. 93, 350--366 (1971; Zbl 0227.41009) Full Text: DOI OpenURL