Lubis, Andri M.T., Carles Siagian, Erick Wonggokusuma, Aldo F Marsetyo, and Bambang Setyohadi. 2017. “Comparison of Glucosamine-Chondroitin Sulfate With and Without Methylsulfonylmethane in Grade I-II Knee Osteoarthritis: A Double Blind Randomized Controlled Trial”. Acta Medica Indonesiana 49 (2):105. https://www.actamedindones.org/index.php/ijim/article/view/168.