Acu, A. M.; Gonska, H.; Raşa, I. Grüss-type and Ostrowski-type inequalities in approximation theory. (English. Russian original) Zbl 1254.41011 Ukr. Math. J. 63, No. 6, 843-864 (2011); translation from Ukr. Mat. Zh. 63, No. 6, 723-740 (2011). MSC: 41A17 26D15 41A36 PDFBibTeX XMLCite \textit{A. M. Acu} et al., Ukr. Math. J. 63, No. 6, 843--864 (2011; Zbl 1254.41011); translation from Ukr. Mat. Zh. 63, No. 6, 723--740 (2011) Full Text: DOI Link
Ostrowski, A. M. On an integral inequality. (English) Zbl 0198.08106 Aequationes Math. 4, 358-373 (1970). PDFBibTeX XMLCite \textit{A. M. Ostrowski}, Aequationes Math. 4, 358--373 (1970; Zbl 0198.08106) Full Text: DOI EuDML