@inbook {IOPORT.01047872,
    author       = {Cherubini, Alessandra and Petrich, Mario},
    title        = {Linear congruences on free monoids.},
    year         = {1992},
    booktitle    = {Words, languages and combinatorics, Kyoto, Japan, August 28--31, 1990},
    isbn         = {981-02-0645-3},
    pages        = {45-51},
    publisher    = {Singapore: World Scientific},
    abstract     = {Summary: The main purpose of this paper is to study the behaviour of linear congruences on a free monoid $X^*$. Their unions and intersections are studied and are described for certain special families of linear congruences. The paper is a summary of the results obtained. The complete results appeared elsewhere [Proc. Am. Math. Soc. 119, No. 3, 719-726 (1993; Zbl 0799.20048)].},
    identifier   = {01047872},
}