Mohamed, E., Ibrahim, A., Alkhatim, M., Mohammed, L., Musa, H. and Idris, A. A. (2022) “Serum Vitamin D and Anti-Cyclic Citrullinated Peptide Levels in Rheumatoid Arthritis Patients”, Biomedical Research and Therapy, 9(7), pp. 5149-5153. doi: 10.15419/bmrat.v9i7.750.