‘Aliyah, Dheva, Nikken Puspita, and Redemtus Tjahjana. “Clean Modules Constructed from the External Direct Sum of Clean Modules”. International Journal Of Mathematics And Computer Research 13, no. 7 (July 30, 2025): 5492-5495. Accessed May 19, 2026. https://www.ijmcr.everant.org/index.php/ijmcr/article/view/1014.