Between Mikhail Kravchuk and Efim Zelmanov who wrote more articles on mathematics? 
Mikhail Kravchuk: Mykhailo Pylypovych Kravchuk, also Krawtchouk (Ukrainian: Миха́йло Пили́пович Кравчу́к ) (September 27, 1892 – March 9, 1942), was a Soviet Ukrainian mathematician who, despite his early death, was the author of around 180 articles on mathematics. 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.
i don't know