ALT, Heinrich. Die a priori en die a priori sintese in die Wysbegeerte. Tydskrif vir Christelike Wetenskap | Journal for Christian Scholarship, [S. l.], v. 54, n. 4, p. 121–137, 2019. Disponível em: https://pubs.ufs.ac.za/index.php/tcw/article/view/435. Acesso em: 18 sep. 2025.