BHUVANESWARI, K.; KALYANI, T. Recognizable iso-triangular picture languages. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 42, p. 436–448, 2019. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/7223. Acesso em: 27 oct. 2026.