Columbia subject headings:
Geographers--Soviet Union--Correspondence.
Potanin, G. N. (Grigoriĭ Nikolaevich), 1835-1920.
Harvard subject headings:
Geographers--Soviet Union--Correspondence.
Potanin, G. N. (Grigoriĭ Nikolaevich), 1835-1920
Princeton subject headings:
Geographers--Soviet Union--Correspondence.
Potanin, G. N. (Grigoriĭ Nikolaevich), 1835-1920.