On the size of independent systems of equations in semigroups

Karhumäki, J., & Plandowski, W. (1994). On the size of independent systems of equations in semigroups. In Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) (Vol. 841 LNCS, pp. 443–452). Springer Verlag. https://doi.org/10.1007/3-540-58338-6_91