^Amadon, D. (1982). The genera of booted eagles: Aquila and relatives. Journal of the Yamashina Institute for Ornithology, 14(2-3), 108-121.
^Lerner, H. R., Klaver, M. C., & Mindell, D. P. (2008). Molecular phylogenetics of the Buteonine birds of prey (Accipitridae). The Auk, 125(2), 304-315.
^Lerner, H. R., & Mindell, D. P. (2005). Phylogeny of eagles, Old World vultures, and other Accipitridae based on nuclear and mitochondrial DNA. Molecular Phylogenetics and Evolution, 37(2), 327-346.