Karim Kadhim, Hatem, and Nawar Nasser Shaaban. “General Knowledge Framework For The German Cost Accounting System (GPK): A Theoretical Perspective”. Akkad Journal of Contemporary Management Studies  2, no. 4 (March 11, 2023): 202–215. Accessed October 31, 2025. https://journal.acefs.org/index.php/AJCMS/article/view/178.