Bulletin de l'Académie Impériale des Sciences de St.-Pétersbourg. 5. Série. Izvestiya Imperatorskoy Akademii Nauk. Russian.

Journal

http://www.mathnet.ru/php/archive.phtml?jrnid=im&wshow=contents&option_lang=eng

Formerly: Bull. de St. Pétersb.
Continued as: Leningrad, Bull. Ac. Sc. (6)

No longer indexed. Journal abbreviations vary in sources