[1]
Oļukalns, A. 2006. Spread of Heracleum Sosnowsky Manden in Madona District (Latvia) and Its Control Possibilities. ENVIRONMENT. TECHNOLOGIES. RESOURCES. Proceedings of the International Scientific and Practical Conference. 1, (Jun. 2006), 200–205. DOI:https://doi.org/10.17770/etr2003vol1.2007.