What scientific carreer do both Efim Zelmanov and Lazar Lyusternik have in common?
Efim Zelmanov Efim Isaakovich Zelmanov (Russian: Ефи́м Исаа́кович Зе́льманов ; born 7 September 1955 in Khabarovsk) is a Russian-American mathematician, known for his work on combinatorial problems in nonassociative algebra and group theory, including his solution of the restricted Burnside problem. He was awarded a Fields Medal at the International Congress of Mathematicians in Zürich in 1994.
Yuri Kondratyuk Yuriy Vasilievich Kondratyuk (real name Aleksandr Ignatyevich Shargei, Ukrainian: Олександр Гнатович Шаргей , "Oleksandr Hnatovych Sharhei") (June 21, 1897 – February 1942) was a Soviet engineer and mathematician. He was a pioneer of astronautics and spaceflight, a theoretician and a visionary who, in the early 20th century, developed the first known lunar orbit rendezvous (LOR), a key concept for landing and return spaceflight from Earth to the Moon. The LOR was later used for the plotting of the first actual human spaceflight to the Moon. Many other aspects of spaceflight and space exploration are covered in his works.