Byoung-Ha Hwang, and Dae-Hyun Kim. “A STUDY ON THE IMMEDIATE EFFECT OF QUADRUPEDAL WALKING EXERCISE OF SANDY GROUND TO REPLACE PUSH UP PLUS EXERCISE”. PalArch’s Journal of Archaeology of Egypt / Egyptology, vol. 17, no. 10, Dec. 2020, pp. 924-8, https://archives.palarch.nl/index.php/jae/article/view/4711.