Pornpan Theprungsimankul, Supaporn Junsank, Aksarapak Abdulloh, & Wirawan Chinviriyasit. (2011). The Effect of Cross-Immunity in a Multi-Strain Epidemic Model. Agriculture and Natural Resources, 45(3), 563–570. Retrieved from https://li01.tci-thaijo.org/index.php/anres/article/view/245333