Noviks, Gotfrīds. “JAUNATNES EKOLOĢISKĀS IZGLĪTOŠANAS PROBLĒMAS”. ENVIRONMENT. TECHNOLOGY. RESOURCES. Proceedings of the International Scientific and Practical Conference 1 (June 20, 1999): 123–125. Accessed April 24, 2025. https://journals23.rta.lv/index.php/ETR/article/view/1893.