Rojas, L. M.; Ramírez, Y.; McNeil, R.; Mitchell, M.; Marín, G. (2004). "Retinal Morphology and Electrophysiology of Two Caprimulgiformes Birds: The Cave-Living and Nocturnal Oilbird (Steatornis caripensis), and the Crepuscularly and Nocturnally Foraging Common Pauraque (Nyctidromus albicollis)". Brain, Behavior and Evolution. 64 (1): 19–33. doi:10.1159/000077540. PMID15051964.
Rojas, L. M.; Ramírez, Y.; McNeil, R.; Mitchell, M.; Marín, G. (2004). "Retinal Morphology and Electrophysiology of Two Caprimulgiformes Birds: The Cave-Living and Nocturnal Oilbird (Steatornis caripensis), and the Crepuscularly and Nocturnally Foraging Common Pauraque (Nyctidromus albicollis)". Brain, Behavior and Evolution. 64 (1): 19–33. doi:10.1159/000077540. PMID15051964.