Sahay, A. S., A. N. Fitriah, and E. Christian. “Sistem Pakar Diagnosa Penyakit Lambung Berbasis Website Menggunakan Metode Forward Chaining & Certainty Factor”. Journal of Information Technology and Computer Science, vol. 1, no. 3, Dec. 2021, pp. 192-01, doi:10.47111/jointecoms.v1i3.8813.