de Freitas, S. A., and G. A. Myburgh. “The Relevance of Science for the Protection of the Unborn”. Tydskrif Vir Christelike Wetenskap | Journal for Christian Scholarship, vol. 45, no. 1 - 2, June 2009, pp. 61-85, https://pubs.ufs.ac.za/index.php/tcw/article/view/164.