Jan Ove Gjershaug (2006) Taxonomy and conservation status of hawk-eagles (genus Nisaetus) in South-East Asia. Thesis. Norwegian University of Science and Technology Plena teksto
umich.edu
www-personal.umich.edu
Lerner, H. R. L.; D. P. Mindell (2005). "Phylogeny of eagles, Old World vultures, and other Accipitridae based on nuclear and mitochondrial DNA". Molecular Phylogenetics and Evolution 37:327–346 PDFArkivigite je 2011-06-06 per la retarkivo Wayback Machine
web.archive.org
Lerner, H. R. L.; D. P. Mindell (2005). "Phylogeny of eagles, Old World vultures, and other Accipitridae based on nuclear and mitochondrial DNA". Molecular Phylogenetics and Evolution 37:327–346 PDFArkivigite je 2011-06-06 per la retarkivo Wayback Machine