Winter ranging behaviour of a greater spotted eagle (Aquila clanga) in southeast Spain during four consecutive years
Pérez-García, Juan M., Sellis, Urmas, Väli, Ülo
Colour ringing of the Spotted Eagles (Aquila pomarina, Aquila clanga and their hybrids) in Europe - a review
Dravecký, Miroslav, Sellis, Urmas, Bergmanis, Ugis, Dombrovski, Valery, Lontkowski, Jan, Maciorowski, Grzegorz, Maderič, Boris, Meyburg, Bernd-Ulrich, Mizera, Tadeusz, Stój, Marian, Treinys, Rimgaudas, Wójciak, Janusz