Coetzee, H., W. Nell, and L. van Rensburg. “An Intervention Program Based on Plant Surrogates As Alternatives to the Use of Southern Ground-Hornbills in Cultural Practices”. Ethnobotany Research and Applications, vol. 12, May 2014, pp. 155-64, https://ethnobotanyjournal.org/index.php/era/article/view/973.