Fatimah Hasibuan, S., R. Sutatminingsih, and B. Maulina Ozar. “Concrete Pictorial Abstract (CPA) Method-Based Intervention to Improve Understanding of Two-Digit Addition Concepts in Children With Mathematics Learning Difficulties”. ATTA`DIB, vol. 9, no. 3, Dec. 2025, pp. 760-83, https://ejournal.uika-bogor.ac.id/index.php/at-tadib/article/view/22314.