ÉSIK, Z. The Equational Theory of Fixed Points with Applications to Generalized Language Theory. BRICS Report Series, [S. l.], v. 8, n. 22, 2001. DOI: 10.7146/brics.v8i22.21683. Disponível em: https://tidsskrift.dk/brics/article/view/21683. Acesso em: 21 may. 2024.