Question: Between Mikhail Kravchuk and Efim Zelmanov who wrote more articles on mathematics? 
Sentence (from "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.
Relevant evidence: Yes