Volker Diekert. A Remark on Trace Equations. In Christian Freksa, Matthias Jantzen, Rüdiger Valk, editors, Foundations of Computer Science: Potential - Theory - Cognition, to Wilfried Brauer on the occasion of his sixtieth birthday. Volume 1337 of Lecture Notes in Computer Science, pages 251-260, Springer, 1997. [doi]
Abstract is missing.