Sparrows, Barcelona: Lynx Edicions, pp. 404–459, ISBN 978-84-96553-50-7 Irested, Martin; Jønsson, Knud A; Fjeldså, Jon; Christidis, Les and Per GP Ericson
Version 8.1. International Ornithologists' Union. Retrieved 29 March 2018. Irested, Martin; Fuchs, J; Jønsson, KA; Ohlson, JI; Pasquet, E; Ericson, Per G