Columbia subject headings:
Aeronautics--Russia--History.
Aerospace engineering--Russia--History.
Sikorsky, Igor Ivan, 1889-1972.
T︠S︡iolkovskiĭ, K. (Konstantin), 1857-1935.
Vorobʹev, B. N. (Boris Nikitich)--Friends and associates.
Zeppelin, Ferdinand, Graf von, 1838-1917.
Harvard subject headings:
Aeronautics--Russia--History.
Aerospace engineering--Russia--History.
Sikorsky, Igor Ivan, 1889-1972
T͡Siolkovskiĭ, K. (Konstantin), 1857-1935.
Vorobʹev, B. N. (Boris Nikitich)--Friends and associates.
Zeppelin, Ferdinand, Graf von, 1838-1917
Princeton subject headings:
Aeronautics--Russia--History.
Aerospace engineering--Russia--History.
Sikorsky, Igor Ivan, 1889-1972.
T︠S︡iolkovskiĭ, K. (Konstantin), 1857-1935.
Vorobʹev, B. N. (Boris Nikitich)--Friends and associates.
Zeppelin, Ferdinand, Graf von, 1838-1917.