Wanthat, I.- on, and A. Nokkaew. “THE DEVELOPMENT OF MATHEMATICAL CONCEPTS ON RECTANGLE FOR PRATHOMSUKSA 4 STUDENTS USING VAN HIELE’S THEORY AND VIRTUAL MANIPULATIVE”. Journal of Buddhist Education and Research (JBER), vol. 9, no. 3, Sept. 2023, pp. 193-06, https://so06.tci-thaijo.org/index.php/jber/article/view/268107.