NOVIK, Gotfrid. ENVIRONMENTALLY SUSTAINABLE TECHNOLOGIES AND ENVIRONMENTAL QUALITY INDICATORS. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference, Rezekne, Latvia, v. 1, p. 122–127, 2001. DOI: 10.17770/etr2001vol1.1945. Disponível em: https://journals.ru.lv/index.php/ETR/article/view/1945.. Acesso em: 5 may. 2024.