Range map of Gull-billed tern.    Year-round  Breeding  Nonbreeding
BirdLife International. 2018. Gelochelidon nilotica. The IUCN Red List of Threatened Species 2018: e.T62026481A132670500. https://dx.doi.org/10.2305/IUCN.UK.2018-2.RLTS.T62026481A132670500.en. Downloaded on 31 December 2018.
Cephas