G. R.  Graves and Newfield, N. L., ?Diagnoses of hybrid hummingbirds (Aves: Trochilidae). 1. Characterization of Calypte anna x Stellula calliope and the possible effects of egg volume on hybridization potential?, Proceedings of the Biological Society of Washington, vol. 109, pp. 755-763, 1996.

G. R.  Graves, ?Diagnoses of hybrid hummingbirds (Aves: Trochilidae). 6. An intergeneric hybrid, Aglaiocercus kingi X Metallura tyrianthina, from Venezuela?, Proceedings of the Biological Society of Washington, vol. 111, pp. 511-520, 1998.

G. R.  Graves, ?Diagnoses of hybrid hummingbirds (Aves: Trochilidae). 8. A provisional hypothesis for the hybrid origin of Zodalia glyceria (Gould, 1858)?, Proceedings of the Biological Society of Washington, vol. 112, pp. 491-502, 1999.

G. R.  Graves, ?Diagnoses of hybrid hummingbirds (Aves: Trochilidae). 9. Confirmation of the hybrid origin of Coeligena purpurea Gould, 1854?, Proceedings of the Biological Society of Washington, vol. 114, pp. 42-50, 2001.

G. R.  Graves, ?Diagnoses of hybrid hummingbirds (Aves: Trochilidae). 10. Cyanomyia salvini Brewster, 1893, is an intergeneric hybrid of Amazilia violiceps and Cynanthus latirostris?, Proceedings of the Biological Society of Washington, vol. 116, pp. 293-300, 2003.

G. R.  Graves, ?Diagnoses of hybrid hummingbirds (Aves: Trochilidae). 11. Documentation of an intergeneric woodstar hybrid, Calliphlox mitchellii X Chaetocercus mulsant?, Proceedings of the Biological Society of Washington, vol. 116, pp. 820-826, 2003.

G. R.  Graves, ?Diagnoses of hybrid hummingbirds (Aves: Trochilidae). 13. An undescribed intrageneric combination, Heliodoxa imperatrix X Heliodoxa jacula?, Proceedings of the Biological Society of Washington, vol. 117, pp. 10-16, 2004.