. . . . . . . . . "Hydroprogne caspia" . . "Larus argentatus" . . "Paul Tavares. 2012. Hydroprogne caspia other species in group Larus argentatus. iNaturalist.org. Accessed at <https://www.inaturalist.org/observations/8820209> on 05 Apr 2018." . . . . "http://iNaturalist.org is a place where you can record what you see in nature, meet other nature lovers, and learn about the natural world." .