(en) Sangster G. (2022). The taxonomic status of Palearctic and Nearctic populations of northern goshawk Accipiter gentilis (Aves, Accipitridae): New evidence from vocalisations. Vertebrate Zoology 72:445-456 DOI:10.3897/vz.72.e85419
(en) Chesser, R.T.et al. (2023) Sixty-fourth Supplement to the American Ornithological Society’s Check-list of North American Birds. Ornithology 140(3) DOI:10.1093/ornithology/ukad023
