Ferguson-Lees, James; Christie, David A. (2001). Raptors of the World. Illustrated by Kim Franklin, David Mead, and Philip Burton. Houghton Mifflin. ISBN978-0-618-12762-7. Henta 26. mai 2011.
doi.org
dx.doi.org
Paton, P. W. C.; Messina, F. J.; Griffin, C. R. (1994). «A Phylogenetic Approach to Reversed Size Dimorphism in Diurnal Raptors». Oikos71 (3): 492–498. doi:10.2307/3545837.
Ward, J.; McCafferty, D.; Houston, D.; Ruxton, G. (2008). «Why do vultures have bald heads? The role of postural adjustment and bare skin areas in thermoregulation». Journal of Thermal Biology33 (3): 168–173. doi:10.1016/j.jtherbio.2008.01.002.
Thomson, A. L.; Moreau, R. E. (1957). «Feeding Habits of the Palm-Nut Vulture Gypoheerax». Ibis99 (4): 608–613. doi:10.1111/j.1474-919X.1957.tb03053.x.
Shiu, H. J.; Tokita, K. I.; Morishita, E.; Hiraoka, E.; Wu, Y.; Nakamura, H.; Higuchi, H. (2006). «Route and site fidelity of two migratory raptors: Grey-faced Buzzards Butastur indicus and Honey-buzzards Pernis apivorus». Ornithological Science5 (2): 151–156. doi:10.2326/osj.5.151.
Gill, Frank; Donsker, David; Rasmussen, Pamela, red. (January 2024). «Raptors». IOC World Bird List Version 14.1. International Ornithologists' Union. Henta 21. mai 2024.