Columbia subject headings:
Geologists--Soviet Union--Correspondence.
Vernadskai︠a︡, Natalii︠a︡ Egorovna, 1860-1943.
Vernadskiĭ, V. I. (Vladimir Ivanovich), 1863-1945.
Harvard subject headings:
Princeton subject headings:
Geologists--Soviet Union--Correspondence.
Vernadskai︠a︡, Natalii︠a︡ Egorovna, 1860-1943--Correspondence.
Vernadskiĭ, V. I. (Vladimir Ivanovich), 1863-1945--Correspondence.