XIA, Y.; ZHANG, X.; LUO, X.; ZHU, Q. Modelling of Ontology-based Service Compositions using Petri Net. Elektronika ir Elektrotechnika, [S. l.], v. 19, n. 2, p. 75-78, 2013. DOI: 10.5755/j01.eee.19.2.3474. Disponível em: https://eejournal.ktu.lt/index.php/elt/article/view/3474. Acesso em: 25 feb. 2021.