Attributes / relations provided by
♦ ¹del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona.
♦ ²Proteles cristata, C. E. Koehler and P. R. K. Richardson, MAMMALIAN SPECIES No. 363, pp. 1-6 (1990)