PUŽULE, Valentīna; NOVIKS, Gotfrids. KUPRAVA CLAY DEPOSIT RESEARCH COMPARISON. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference, Rezekne, Latvia, v. 1, p. 236–240, 2019. DOI: 10.17770/etr2019vol1.4164. Disponível em: https://journals.rta.lv/index.php/ETR/article/view/4164.. Acesso em: 5 may. 2024.