Mayr, Gerald (2003): Phylogeny of early tertiary swifts and hummingbirds (Aves: Apodiformes). Auk 120(1): 145–151. DOI:[0145:POETSA2.0.CO;2 10.1642/0004-8038(2003)120[0145:POETSA]2.0.CO;2]PDF fulltext
Mayr, Gerald (2002): Osteological evidence for paraphyly of the avian order Caprimulgiformes (nightjars and allies). Journal für Ornithologie143: 82–97. PDF fulltext
Mayr, Gerald (2003): Phylogeny of early tertiary swifts and hummingbirds (Aves: Apodiformes). Auk 120(1): 145–151. DOI:[0145:POETSA2.0.CO;2 10.1642/0004-8038(2003)120[0145:POETSA]2.0.CO;2]PDF fulltext