Attributes / relations provided by
♦ ¹Dietary importance of various prey fishes for pikeperch Sander lucioperca (L.) in large shallow lake Võrtsjärv (Estonia), Peeter Kangur, Andu Kangur, and Külli Kangur, Proc. Estonian Acad. Sci. Biol. Ecol., 2007, 56, 2, 154-167
♦ ²del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.