Ward, J.; McCafferty, D.J.; Houston, D.C.; Ruxton, G.D. (april 2008). »Why do vultures have bald heads? The role of postural adjustment and bare skin areas in thermoregulation«. Journal of Thermal Biology. 33 (3): 168–173. doi:10.1016/j.jtherbio.2008.01.002.{{navedi časopis}}: Vzdrževanje CS1: samodejni prevod datuma (povezava)
Oaks JL; Gilbert M; Virani MZ; Watson RT; Meteyer CU; in sod. (2004). »Diclofenac residues as the cause of vulture population decline in Pakistan«. Nature. 427 (6975): 630–3. doi:10.1038/nature02317. PMID14745453.
Oaks JL; Gilbert M; Virani MZ; Watson RT; Meteyer CU; in sod. (2004). »Diclofenac residues as the cause of vulture population decline in Pakistan«. Nature. 427 (6975): 630–3. doi:10.1038/nature02317. PMID14745453.