Primary references

• Vigors, N.A. 1825. Observations on the Natural Affinities that connect the Orders and Families of Birds. Transactions of the Linnean Society of London 14(3): 395-517. BHLReference page. 

Additional references

• Barrowclough, G., Groth, J. G., & Mertz, L. A. (2006). The RAG-1 exon in the avian order Caprimulgiformes: Phylogeny, heterozygosity, and base composition. Molecular Phylogenetics and Evolution 41: 238–248.
• Larsen, C., Speed, M., Harvey, N., & Noyes, H. A. (2007). A molecular phylogeny of the nightjars (Aves: Caprimulgidae) suggests extensive conservation of primitive morphological traits across multiple lineages. Molecular Phylogenetics and Evolution 42: 789-796.

• Han, K.-L., Robbins, M.B., Braun, M.J. 2010. A multi-gene estimate of phylogeny in the nightjars and nighthawks (Caprimulgidae). Molecular Phylogenetics and Evolution. 55:443-453. Full article viewReference page. 

• Smith, P. 2017. The identity of Azara's No. 315 “Ibiyau de cola extraña” and No. 316 “Ibiyau anónimo” (Aves: Caprimulgidae). Zootaxa 4337(4): 595–599. DOI: 10.11646/zootaxa.4337.4.10 . Reference page.