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Stresemann, Erwin (1928). "Die Vögel der Elburs Expedition 1927". Journal of Ornithology (in German). 76 (2): 313–326. doi:10.1007/BF01940684. S2CID27450092.
Laiolo, P.; Bignal, E.M.; Patterson, I.J. (1998). "The dynamics of parental care in Choughs (Pyrrhocorax pyrrhocorax)". Journal of Ornithology. 139 (3): 297–305. doi:10.1007/BF01653340. S2CID42610400.
"Red-billed Chough". Durrell Wildlife Conservation Trust. Archived from the original on 27 September 2021. Retrieved 15 July 2019.
"Choughs: Field Programme". Birds on the Edge. Durrell Wildlife Conservation Trust. Archived from the original on 23 December 2018. Retrieved 15 July 2019.