A. Safi, Mohammad-Ayman, and Dhiya T. Houssien. 1981. “Anti-Cyclic Citrullinated Peptide and Rheumatoid Factor (Prevalence and Association) in Saudi Rheumatoid Arthritis Patients”. Journal of King Abdulaziz University: Medical Sciences 25 (2):1-10. https://doi.org/10.4197/Med.25-2.1.