Brown, CJ, PA Bridgeford, SG Braine, M Paxton, and W Versfeld. “Breeding Data on the Birds of Namibia: Laying Months, Colony and Clutch Sizes and Egg Measurements”. Biodiversity Observations (September 5, 2015): 92–196. Accessed June 29, 2022. https://journals.uct.ac.za/index.php/BO/article/view/284.