Skute A, Osipovs S, Vardanjans D. Determining the Isotopic Composition of Nitrate in the River Daugava and Loads of Nitrogen to the Gulf of Riga. ETR [Internet]. 2015 Jun. 17 [cited 2024 May 2];2:280-3. Available from: https://journals.ru.lv/index.php/ETR/article/view/249