Abd el-Khallek, E.Y. et al. 2018. Serum Level of Rheumatoid Factor and Anti-Nuclear Anti bodies in Patients with Helicobacter Pylori Related Gastric Lesions. Journal of medical and pharmaceutical sciences. 2, 3 (Sep. 2018), 72–67. DOI:https://doi.org/10.26389/AJSRP.S070518.