San Sebastián , A, et al. “EFFECTIVENESS OF INDIVIDUAL VS GROUP PHYSIOTHERAPY IN PATIENTS WITH SUBACROMIAL IMPINGEMENT SYNDROME: RANDOMIZED CONTROLLED TRIAL”. Cuestiones De Fisioterapia, vol. 46, no. 3, June 2017, pp. 163-7, https://cuestionesdefisioterapia.com/index.php/cf/article/view/182.