N. A. Yakovlev · 2 obras en el catálogoObrasSSokrashchenie primeneniya ruchnogo truda v ugol'noi promyshlSokrashchenie primeneniya ruchnogo truda v ugol'noi promyshlennostiTTekhnicheskii progress i trud v ugol'noi promyshlennostiTekhnicheskii progress i trud v ugol'noi promyshlennosti
SSokrashchenie primeneniya ruchnogo truda v ugol'noi promyshlSokrashchenie primeneniya ruchnogo truda v ugol'noi promyshlennosti
TTekhnicheskii progress i trud v ugol'noi promyshlennostiTekhnicheskii progress i trud v ugol'noi promyshlennosti