by Frederick C. Durant, V. N. SokolʹskiÄ, Institut istorii estestvoznaniiï¸ a︡ i tekhniki (Akademiiï¸ a︡ nauk SSSR), Sovetskoe natï¸ s︡ionalʹnoe obʺedinenie istorikov estestvoznaniiï¸ a︡ i tekhniki, International Astronautical Congress (18th 1967 Belgrade)