Columbia subject headings:
Harvard subject headings:
Astronautics--Soviet Union
Gagarin, Yuri Alekseyevich, 1934-1968
Korolev, Sergeĭ Pavlovich, 1907-1966
Princeton subject headings:
Astronautics--Soviet Union--Biography.
Gagarin, Yuri Alekseyevich, 1934-1968.
Korolev, Sergeĭ Pavlovich, 1907-1966.