K. DHURAI; A. KARPAGAM. New Membership Function and New Ranking Function on Heptagon Fuzzy Number. International Journal of Mathematics And its Applications, [S. l.], v. 5, n. 4 - F, p. 875–878, 2017. Disponível em: https://ijmaa.in/index.php/ijmaa/article/view/1351. Acesso em: 22 jul. 2024.