Sewell, W. E. Generalized derivatives and approximation by polynomials. (English) Zbl 0016.10702 Trans. Am. Math. Soc. 41, 84-123 (1937). PDFBibTeX XMLCite \textit{W. E. Sewell}, Trans. Am. Math. Soc. 41, 84--123 (1937; Zbl 0016.10702) Full Text: DOI
Sewell, W. E. Generalized derivatives and approximation by polynomials. (English) JFM 63.0258.02 Trans. Amer. math. Soc. 41, 84-123 (1937). Reviewer: Heuser, P., Dr. (Darmstadt) PDFBibTeX XMLCite \textit{W. E. Sewell}, Trans. Am. Math. Soc. 41, 84--123 (1937; JFM 63.0258.02) Full Text: DOI