Niradrop, O., P. Ratanabuth, and K. Poompin. “Physical Fitness Norms for Grade 1 – 6 Students of Ramkhamhaeng University Demonstration Elementary School”. Vajira Medical Journal : Journal of Urban Medicine, vol. 62, no. 2, Apr. 2018, pp. 109-18, https://he02.tci-thaijo.org/index.php/VMED/article/view/195638.