Craig, C. A., C. A. Hunter, A. J. Craig, and P. E. Hulley. “Birds Feeding on Aloe Nectar: Do Camera Traps and Point Counts Produce Comparable Data?”. Biodiversity Observations, vol. 8, Aug. 2017, pp. 44: 1 - 10, https://journals.uct.ac.za/index.php/BO/article/view/467.