Comparison of efficacy of a supervised versus non-supervised physical therapy exercise program on the pain, functionality and quality of life of patients with non-specific chronic low-back pain: a randomized controlled trial - Matarán-Peñarrocha G.A.; Lara Palomo I.C.; Antequera Soler E.; Gil-Martínez E.; Fernández-Sánchez M.; Aguilar-Ferrándiz M.E.; Castro-Sánchez A.M. (CLINICAL REHABILITATION, 2020)