Stoker, P. H., and H. G. (Henk) Stoker. “Vrugbare Wetenskappe”. Tydskrif vir Christelike Wetenskap | Journal for Christian Scholarship 49, no. 4 (December 20, 2013): 47-67. Accessed April 20, 2024. https://pubs.ufs.ac.za/index.php/tcw/article/view/360.