ANDERSEN, D. S.; PEDERSEN, L. H.; HÜTTEL, H.; KLEIST, J. Objects, Types and Modal Logics. BRICS Report Series, [S. l.], v. 3, n. 49, 1996. DOI: 10.7146/brics.v3i49.20051. Disponível em: https://tidsskrift.dk/brics/article/view/20051. Acesso em: 25 apr. 2024.