Nikol’skij, S. M. Sur les theoremes d’immersion, prolongement et approximation des fonctions derivables des plusieurs variables. (Romanian) Zbl 0269.26011 Acad. Republ. popul. Romine, Fil. Cluj, Inst. Calcul, Studii Cerc. Mat. 12, 97-143 (1961). MSC: 26B05 41A65 41A30 46E35 PDFBibTeX XMLCite \textit{S. M. Nikol'skij}, Acad. Repub. Popul. Romîne, Fil. Cluj, Inst. Calcul, Studii Cerc. Mat. 12, 97--143 (1961; Zbl 0269.26011)
Tatarskiĭ, V. I. The primitive functional and its application to the integration of some equations with functional derivatives. (Über das primitive Funktional und seine Anwendung auf die Integration gewisser Gleichungen in Funktionalableitungen.) (Russian) Zbl 0206.12203 Usp. Mat. Nauk 16, No. 4(100), 179-186 (1961). Reviewer: K. Krickeberg (M. R. 25, 423) MSC: 46E10 41A65 PDFBibTeX XMLCite \textit{V. I. Tatarskiĭ}, Usp. Mat. Nauk 16, No. 4(100), 179--186 (1961; Zbl 0206.12203)