MATISOVS, Ivars. ECOLOGICAL EXPEDITION AS EFFECTIVE FORM OF ENVIRONMENTAL RESEARCH AND ECOLOGICAL EDUCATION. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference, Rezekne, Latvia, v. 1, p. 254–261, 2007. DOI: 10.17770/etr2007vol1.1730. Disponível em: https://journals.rta.lv/index.php/ETR/article/view/1730.. Acesso em: 21 nov. 2024.