Salima Mohamed Khader and Sanaa Ahmed Alshhomi (2025) “Van Kampen Diagrams and Pictures: Definitions, Operations, and Conversions”, African Journal of Advanced Pure and Applied Sciences (AJAPAS), 4(3), pp. 272–284. Available at: https://aaasjournals.com/index.php/ajapas/article/view/1384 (Accessed: 5 December 2025).