Salima Mohamed Khader, Sanaa Ahmed Alshhomi. Van Kampen Diagrams and Pictures: Definitions, Operations, and Conversions. AfJ Adv Pure Appl Sci [Internet]. 2025 Aug. 18 [cited 2025 Dec. 5];4(3):272-84. Available from: https://www.aaasjournals.com/index.php/ajapas/article/view/1384