Yerbol Kenzhegaliuly Mukhambetgaliyev (2020) «HIGH-ASH COALS - POTENTIAL RESOURCES FOR FERROALLOY PRODUCTION », Academic Journal of Physical and Chemical Sciences, (3), сс. 12–19. доступно на: http://89.250.84.46/reports-science/article/view/801 (просмотрено: 13 декабрь 2025).