Changes in nutrient emissions, fluxes and retention in a North-Eastern European lowland drainage basinMourad, Daniel S.J.; Perk, Marcel van der; Piirimäe, KristjanEnvironmental monitoring and assessment2006 / 1, p. 415-448 : illhttps://link.springer.com/content/pdf/10.1007/s10661-005-9071-y.pdf