Defining Chlorophyll-a Reference Conditions in European Lakes - Sandra Poikāne; Maria Helena Alves; Christine Argillier; Marcel van den Berg; Fabio Buzzi; Eberhard Hoehn; Caridad de Hoyos; Ivan Karottki; Christophe Laplace-Treyture; Anne Lyche Solheim; José Ortiz-Casas; Ingmar Ott; et al. (Environmental Management, 2010)