00523naa#a2200169#i#450# EN\\bibl\41608 20250502222042.5 2500-3372 20201231b2020####ek#y0engy0150####ca RU Factor Model of Labor Productivity in the Coal Industry Journal article Kemerovo Kemerovo State University 2020 10 с. Journal article local Kharlampenkov Evgeny Ivanovich Kudryashova Irina Anatol'evna jstrategizing.kemsu.ru