Jafar, Muhammad. “The Cardio Respiratory Endurance Level of the Penjaskesrek Gymnastics Instructors in the Education and Teacher Training Faculty of Universitas Syiah Kuala”. The Journal of Educational Development 6, no. 1 (January 17, 2018): 36-43. Accessed May 2, 2024. https://journal.unnes.ac.id/sju/jed/article/view/20687.