Wajs , Ewa. 2006. Записки Горного института 167 (2), 177-78. https://pmi.spmi.ru/pmi/article/view/7990.

Wajs , Ewa. 2006. "Adaptation of Geographical Information System in Net Water-Supply and Sewage Enterprises". Journal of Mining Institute 167 (2), 177-78. https://pmi.spmi.ru/pmi/article/view/7990.