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.
♦ ²Ovibos moschatus, Peter C. Lent, MAMMALIAN SPECIES No. 302, pp. 1-9 (1988)