Mielczarek , M. (2007). Записки Горного института, 170(2), 242-245. извлечено от https://pmi.spmi.ru/pmi/article/view/7762

Mielczarek , M. (2007). The directions of development as a chance for small family farms. Journal of Mining Institute, 170(2), 242-245. Retrieved from https://pmi.spmi.ru/pmi/article/view/7762