BRODAL, G. S.; SKYUM, S. The Complexity of Computing the k-ary Composition of a Binary Associative Operator. BRICS Report Series, [S. l.], v. 3, n. 42, 1996. DOI: 10.7146/brics.v3i42.20024. Disponível em: https://tidsskrift.dk/brics/article/view/20024. Acesso em: 25 apr. 2024.