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.
♦ 2THE ROLE OF SEED DISPERSERS IN THE POPULATION DYNAMICS OF THE COLUMNAR CACTUS NEOBUXBAUMIA TETETZO, HÉCTOR GODÍNEZ-ALVAREZ, ALFONSO VALIENTE-BANUET, AND ALBERTO ROJAS-MARTÍNEZ, Ecology, 83(9), 2002, pp. 2617-2629
♦ 3Hummingbirds and the plants they visit in the Tehuacán-Cuicatlán Biosphere Reserve, Mexico, Raúl Ortiz-Pulido, S. Anaid Díaz, Oscar I. Valle-Díaz and Ana D. Fisher, Revista Mexicana de Biodiversidad 83: 152-163, 2012