Socio-Cultural Factors and Experience of Chronic Low Back Pain: a Spanish and Brazilian Patients' Perspective. A Qualitative Study - Rodrigues-de-Souza, D P; Palacios-Ceña, D; Moro-Gutiérrez, L; Camargo, P R; Salvini, T F; Alburquerque-Sendín, F (PLoS One, 2016)