Christian Choffrut, Karel Culik II. On Extendibility of Unavoidable Sets. In Max Fontet, Kurt Mehlhorn, editors, STACS 84, Symposium of Theoretical Aspects of Computer Science, Paris, France, 11-13 April, 1984, Proceedings. Volume 166 of Lecture Notes in Computer Science, pages 326-338, Springer, 1984.
Abstract is missing.