Humbser, Jorge, et al. “Reproductive Biology of the Purple-Throated Sunangel Heliangelus Viola (Trochilidae) in the Southern Andes of Ecuador”. Revista Ecuatoriana de Ornitología, vol. 12, no. 1, June 2026, pp. 20-31, https://doi.org/10.18272/reo.v12i1.3872.