Sarveazad, A., M. Bahardoust, J. Shamseddin, and M. Yousefifard. “Prevalence of Anal Fistulas: A Systematic Review and Meta-Analysis”. Gastroenterology and Hepatology from Bed to Bench, Vol. 15, no. 1, Jan. 2022, doi:10.22037/ghfbb.vi.2365.