\Chapter{Authors' Addresses}

Bettina Eick

Fachbereich f\"ur Mathematik und Informatik, Technische Universit\"at
Braunschweig, 38106 Braunschweig, Germany

www-public.tu-bs.de:8080/$\sim$beick

beick@tu-bs.de

\bigskip

Charles R.B. Wright

Department of Mathematics, University of Oregon, Eugene, Oregon 97403, U.S.A.

www.uoregon.edu/$\sim$wright

wright@math.uoregon.edu