Multiple PRP injections are more effective than single injections and hyaluronic acid in knees with early osteoarthritis: a randomized, double-blind, placebo-controlled trial. - Görmeli G; Görmeli CA; Ataoglu B; Çolak C; Aslantürk O; Ertem K (Knee surgery, sports traumatology, arthroscopy : official journal of the ESSKA, 2017)