PALSBERG, J.; SCHWARTZBACH, M. I. Substitution Polymorphism for Object-Oriented Programming. DAIMI Report Series, [S. l.], v. 19, n. 305, 1990. DOI: 10.7146/dpb.v19i305.6698. Disponível em: https://tidsskrift.dk/daimipb/article/view/6698. Acesso em: 8 may. 2024.