Sobolev, Sergei L., Sur un théorème d'analyse fonctionnelle, Rec. Mat. (Matematicheskiĭ Sbornik), 1938, 4(46) (3): 471–497, Zbl 0022.14803外部链接存在于|journal= (帮助) (in Russian language, with French language Abstract). The paper where Sergei Sobolev proved his Sobolev embedding theorem, introducing and using integral operators very similar to mollifiers, without naming them.
Jean Leray. La vie et l'œuvre de Serge Sobolev. [The life and works of Sergeĭ Sobolev]. Comptes Rendus de l'Académie des Sciences. Série Générale. La Vie des Sciences, vol. 7 (1990), no. 6, pp. 467–471.
M. M. Lavrent'ev, Yu. G. Reshetnyak, A. A. Borovkov, S. K. Godunov, T. I. Zelenyak and S. S. Kutateladze.Remembrances of Sergei L'vovich Sobolev.[永久失效連結] Siberian Mathematical Journal, vol. 30 (1989), no. 3, pp. 502–504