Journal Article
Gahr, M.: The neural song control system of hummingbirds: A comparison with swifts, vocal learning (songbirds) and non-learning (sub-oscines) passerines, vocal learning (budgerigars) and non-learning (dove, owl, gull, quail, chicken) non-passerines. The Journal of Comparative Neurology
426 (2), pp. 182 - 196 (2000)