OĻUKALNS, A. Spread of Heracleum Sosnowsky Manden in Madona District (Latvia) and Its Control Possibilities. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference, Rezekne, Latvia, v. 1, p. 200–205, 2006. DOI: 10.17770/etr2003vol1.2007. Disponível em: https://journals.rta.lv/index.php/ETR/article/view/2007.. Acesso em: 4 may. 2024.