Columbia subject headings:
Harvard subject headings:
Hydrogeology.
Hydrologists--Soviet Union--Biography.
Ovchinnikov, A. M. (Aleksandr Mikhaĭlovich), 1904-1969.
Princeton subject headings:
Hydrogeology.
Hydrologists--Soviet Union--Biography.
Ovchinnikov, A. M. (Aleksandr Mikhaĭlovich), 1904-1969.