Fontes: http://www.dga.unicamp.br/treinamento/apostilas/apostila_uml.pdf http://www.macoratti.net/vb_uml2.htm http://forumconcurseiros.com/phpbb2/viewtopic.php?t=15669&start=0&postdays=0&postorder=asc& http://www.forumconcurseiros.com/phpbb2/viewtopic.php?t=4984&start=25