Pteroglossus beauharnaesii - Curl-crested Aracari

Hellmayr, C. E. 1928. Auk: 45(3): 293-301.
The Ornithological Collection of the Zoological Museum in Munich

Brush, A. H. 1965. Auk: 82(2): 155-160.
The Structure and Pigmentation of the Feather Tips of the Scaled Cuckoo (Lepidogrammus Cumingi)

Amadon, D. 1966. Condor: 68(3): 263-278.
Avian Plumages and Molts

Brush, A. H. 1967. Wilson Bulletin: 79(3): 322-327.
Additional Observations on the Structure of Unusual Feather Tips

Pearson, D. L. 1971. Condor: 73(1): 46-55.
Vertical Stratification of Birds in a Tropical Dry Forest

Remsen, J. V., Jr., M. A. Hyde and A. Chapman. 1993. Condor: 95(1): 178-192.
The Diets of Neotropical Trogons, Motmots, Barbets and Toucans