ÉSIK, Z.; KUICH, W. Inductive * -Semirings. BRICS Report Series, [S. l.], v. 7, n. 27, 2000. DOI: 10.7146/brics.v7i27.20158. Disponível em: https://tidsskrift.dk/brics/article/view/20158. Acesso em: 16 apr. 2024.