Zapiski Akademii nauk Soi︠u︡za SSR po Otdelenii︠u︡ fiziko-matematicheskikh nauk. Mémoires de l'Académie des sciences de l'URSS. Classe physico-mathématique. VIIIe série.
Akademii︠a︡ nauk SSSR.Otdelenie fiziko-matematicheskikh nauk.
Leningrad : Izd-vo Akademii nauk SSSR,
1926-1930.
Science.
Also available on microfilm from University of Michigan, University Library, Preservation Office Microfilming Unit.

Zapiski Rossīĭskoĭ akademīi nauk po Fiziko-matematicheskomu otdi︠e︡lenīi︠u︡. VIIIe série