Codyks, V. M. Über die Punktmengen, in denen die Ableitung gleich \(+\infty\) bzw. \(- \infty\) ist. (Russian) Zbl 0078.04602 Mat. Sb., N. Ser. 43(85), 429-450 (1958). PDFBibTeX XMLCite \textit{V. M. Codyks}, Mat. Sb., Nov. Ser. 43(85), 429--450 (1958; Zbl 0078.04602)
Codyks, V. M. On sets of points where the derivative is finite or infinite correspondingly. (Russian) Zbl 0079.28001 Dokl. Akad. Nauk SSSR 114, 1174-1176 (1957). PDFBibTeX XMLCite \textit{V. M. Codyks}, Dokl. Akad. Nauk SSSR 114, 1174--1176 (1957; Zbl 0079.28001)
Codyks, V. M. On sets of points where the derivative is \(+\infty\) or \(-\infty\) correspondingly. (Russian) Zbl 0077.27304 Dokl. Akad. Nauk SSSR 113, 36-38 (1957). PDFBibTeX XMLCite \textit{V. M. Codyks}, Dokl. Akad. Nauk SSSR 113, 36--38 (1957; Zbl 0077.27304)