Gamauf A, Gjershaug JO, Rov N, Kvaly K and Haring E (2005). “Species or subspecies? The dilemma of taxonomic ranking of some South-East Asian hawk-eagles (genus Spizaetus)”, Bird Conservation International15, p. 99–117. doi:10.1017/S0959270905000080.
Helbig AJ, Kocum A, Seibold I & Braun MJ (2005) A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level. Molecular phylogenetics and evolution 35(1):147-164 PDFArkivigite je 2014-11-06 per la retarkivo Wayback Machine
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Helbig AJ, Kocum A, Seibold I & Braun MJ (2005) A multi-gene phylogeny of aquiline eagles (Aves: Accipitriformes) reveals extensive paraphyly at the genus level. Molecular phylogenetics and evolution 35(1):147-164 PDFArkivigite je 2014-11-06 per la retarkivo Wayback Machine