APA (7th ed.) Citation

Kagan, V. F. (1944). Lobachevskiĭ. [publisher not identified].

Chicago Style (17th ed.) Citation

Kagan, V. F. Lobachevskiĭ. Moskva: [publisher not identified], 1944.

MLA (9th ed.) Citation

Kagan, V. F. Lobachevskiĭ. [publisher not identified], 1944.