Finite degrees of ambiguity in pattern languages A. Mateescu; A. Salomaa — 1994 RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications
Associative closure and periodicity of ω -words A. Mateescu; G. D. Mateescu — 1998 RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications