ARNONKIJPANICH, B. Department of Mathematics, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand, 40002. Engineering and Applied Science Research, [S. l.], v. 39, n. 4, p. 415–427, 2012. Disponível em: https://ph01.tci-thaijo.org/index.php/easr/article/view/4614. Acesso em: 1 oct. 2026.