Mathematical Analysis of Four Species Model of Mutualism in Competitive Systems. Journal of International Academy of Physical Sciences, [S. l.], v. 12, n. 1-4, p. 151–172, 2008. Disponível em: http://www.iaps.org.in/journal/index.php/journaliaps/article/view/851. Acesso em: 23 oct. 2026.