Johnson, J. A., Watson, R. T., & Mindell, D. P. (2005). Prioritizing species conservation: does the Cape Verde kite exist?. Proceedings of the Royal Society of London B: Biological Sciences, 272(1570), 1365-1371. DOI:10.1098/rspb.2005.3098
hbw.com
Orta, J., Marks, J.S., Garcia, E.F.J. & Kirwan, G.M. (2018). Black Kite (Milvus migrans). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (https://www.hbw.com/node/52978 on 23 June 2018).