Parker, I. S., and A. D. . Graham. “Part I Part I. Policies of Confusion 1960-1978: Elephant Ivory, Rhino Horn and Hippo Teeth”. 2020. Pachyderm, vol. 61, Oct. 2020, pp. 153-60, https://pachydermjournal.org/index.php/pachyderm/article/view/16.