Boonsivanon, Krittachai, and Sarayut thitapars. “An automatic threshold level selection method for AR marker’s tracking under conditions”. Engineering and Applied Science Research 40, no. 4 (September 20, 2014): 605–615. accessed May 12, 2025. https://ph01.tci-thaijo.org/index.php/easr/article/view/21747.