Martínez-Vilalta, A., Motis, A. & Kirwan, G.M. (2019). Whistling Heron (Syrigma sibilatrix). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.).
Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/52672 on 27 March 2019).
Karte: San Jose, 1 April 2007, adapted by Chumwa, 6 May 2008
[GFDL or CC-BY-SA-3.0], via Wikimedia Commons