CHEUNG, K.-S.; CHOW, P. K.-O. A Petri-Net Approach to Refining Object Behavioural Specifications. Informatica, [S. l.], v. 33, n. 2, Disponível em: https://puffbird.ijs.si/index.php/informatica/article/view/240. Acesso em: 23 jun. 2025.