Columbia subject headings:
Harvard subject headings:
Biography--Encyclopedias.
Ethnologists--Russia (Federation)
Gumilev, L. N. (Lev Nikolaevich), 1912-1992--Sources.
Princeton subject headings:
Encyclopedias.
Gumilev, L. N. (Lev Nikolaevich), 1912-1992--Encyclopedias.