Quality of Lake Ecosystems and its Role in the Spread of Invasive Species
Purmalis, Oskars, Grīnberga, Laura, Kļaviņš, Linards, Kļaviņš, Māris
Peat humification character in two ombrotrophic bogs depending on peat properties
Silamiķele, Inese, Nikodemus, Oļgerts, Kalniņa, Laimdota, Purmalis, Oskars, Kļaviņš, Māris
Soil Pollution with Trace Elements in Territories of Military Grounds in Latvia
Kokorīte, Ilga, Kļaviņš, Māris, Šīre, Jānis, Purmalis, Oskars, Zučika, Aija
Peat Humic Substances and Earthworm Biohumus Extracts for Agricultural Applications
Bremanis, Gunārs, Klaviņš, Maris, Purmalis, Oskars, Ziemelis, Raitis, Maļecka, Solveiga
Experimental Study of Peat Humification Indicators
Šīre, Jānis, Kļaviņš, Māris, Purmalis, Oskars, Melecis, Viesturs
Surface Activity of Humic Acids Depending on Their Origin and Humification Degree
Klaviņš, Māris, Purmalis, Oskars