Reference
Swen C. Renner, Karl-Ludwig Schuchmann (2004): Biogeography, geographical Variation, and taxonomy of the hummingbird genera Eugenes Gould, 1856, Sternoclyta Gould, 1858, and Hylonympha Gould, 1873
(Aves: Trochilidae) – Ornithologischer Anzeiger – 43_2: 103 - 114.