Jokar,M H , , Hatef,M R , , Mirfeyzi,S Z , , Zarei,H , and Hashem Zade,K . "Hyaluronic Acid and Platelet-rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review", Journal of Patient Safety & Quality Improvement, 3, 4, 2015, 304-307. doi: 10.22038/psj.2015.5256