European Union action plans for eight priority bird species: Bittern (Botaurus stellaris), Ferruginus duck (Aythya nyroca), Steller's eider (Polystica stelleri), Lammergeier (Gypaetus barbatus), Greater spotted eagle (Aquila clanga), Lesser spotted eagle (Aquila pomarina), Bonelli's eagle (Hieraaetus fasciatus), Little bustard (Tetrax tetrax) - Schaffer, Norbert. (Office for Official Publications of the European Communities, 2000)