Mohammed Abdullah Alhadi, Sulaiman Zaid S Alamri, Ayman Mukhtar A Alzaid, et al. “Rheumatoid Arthritis in Hail Region, Saudi Arabia”. International Journal of Innovative Research in Medical Science, vol. 2, no. 02, Feb. 2017, p. 545 to 551, doi:10.23958/ijirms/vol02-i02/07.