On the equivalence of compositions of morphisms and inverse morphisms on regular languages J. Karhumäki; H. C. M. Kleijn — 1985 RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
Compositional representation of rational functions T. Harju; H. C. M. Kleijn; M. Latteux — 1992 RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
The intersection problem for alphabetic vector monoids T. Harju; N. W. Keesmaat; H. C. M. Kleijn — 1994 RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications