Biometrics of Non-Breeding Immature Mallards (Anas Platyrhynchos) in North-Eastern Poland
Łukasz Jankowiak, Michał Polakowski
Bird migration study-site Siemianówka (E Poland) in 2002-2003
Michał Polakowski, Monika Broniszewska, Alicja Krasnodębska, Tomasz Tumiel, Anna Wnorowska