Soleymani, A. et al. 2019. Validity and Reliability of the Persian Version of the Chronic Pain Grade Questionnaire in Patients with Musculoskeletal Pain. Advances in Nursing & Midwifery. 28, 3 (Oct. 2019), 35–39. DOI:https://doi.org/10.22037/anm.v28i3.24990.