context: 1 May] 1905 to a Russian-Ukrainian working-class family; he graduated from the St.
source: Tikhonov worked as an assistant engineer from 1924 to 1926.
reference_original: Tikhonov trabalhou como um engenheiro assistente de 1924 a 1926.
reference_flipped: Tikhonov trabalhou como uma engenheira assistente de 1924 a 1926.