Mohammad-Ayman A. Safi, Dhia A. Houssien, and David L. Scott. “Disease Activity and Anti-Cyclic Citrullinated Peptide (Anti-CCP) Antibody in Saudi RF-Negative Rheumatoid Arthritis Patients”. Journal of King Abdulaziz University: Medical Sciences, vol. 19, no. 3, July 2023, pp. 3-20, https://journals.kau.edu.sa/index.php/MedSci/article/view/1370.