00521naa#a2200169#i#450# EN\\bibl\41608 20240419223138.5 2500-3372 20210112b2021####ek#y0engy0150####ca RU Factor Model of Labor Productivity in the Coal Industry Journal article Kemerovo Kemerovo State University 2021 10 с. Journal article local Kharlampenkov Evgeny Ivanovich Kudryashova Irina Anatol'evna vestnik-hss.kemsu.ru