Purwaningsih, D., Sukiyanto, and Pardimin. “Developing Smart Nusantara Stairs Media Based On PBL As A Strategy To Improve Addition And Subtraction Learning Outcomes Of Grade 1 Elementary School Students”. International Conference on Elementary Education, Vol. 7, no. 1, Mar. 2025, pp. 160-71, https://proceedings.upi.edu/index.php/icee/article/view/4056.