Lapyingyong, Narubet, Yupin Phiphitthakun, and Channarong Heingraj. “A Study Factor of Teacher’s Knowledge for Learning Mathematics Management in Mathematical Proof”. Ratchaphruek Journal 12, no. 3 (December 29, 2014): 72–79. accessed August 26, 2026. https://so05.tci-thaijo.org/index.php/Ratchaphruekjournal/article/view/240921.