Akademija nauk SSSR
Nauka, 1975
Buku Referensi
Aleksandrova, Z.G., author
Sovetskaya Entsiklopedija, 1969
Buku Referensi
Л. П. Алекторова ...[et al.]
Shkola-Press, 1994
Buku Referensi
Shtevnfeldt, E., author
Progress, [date of publication not identified]
Buku Referensi
Myuller, V.K., author
Sovetskaja-Entsiklopedija, 1969
Buku Referensi