Mohammad-Ayman A. Safi, Dhia A. Houssien and David L. Scott 2023. Disease Activity and Anti-Cyclic Citrullinated Peptide (Anti-CCP) Antibody in Saudi RF-Negative Rheumatoid Arthritis Patients. Journal of King Abdulaziz University: Medical Sciences. 19, 3 (Jul. 2023), 3–20.