Harpreet SINGH, et al. “The Validity and Sensitivity of Rheumatoid Arthritis Pain Scale on a Different Ethnic Group From Indian Rheumatoid Arthritis Patients”. Archives of Rheumatology, vol. 35, no. 1, Mar. 2020, pp. 090-6, doi:10.5606/ArchRheumatol.2020.7348.