ECONOMIC ANALYSIS OF THE NATURAL RESOURCES IN THE DISTRICTS OF VIDZEME REGION. ENVIRONMENT. TECHNOLOGY. RESOURCES. Proceedings of the International Scientific and Practical Conference, [S. l.], v. 1, p. 244–253, 2007. DOI: 10.17770/etr2007vol1.1744. Disponível em: https://archive-journals.rtu.lv/etr/article/view/3622.. Acesso em: 11 mar. 2026.