Alfons Geser Dieter Hofbauer Johannes Waldmann Hans Zantema Finding finite automata that certify termination of string rewriting systems. 471-486 2005 16 Int. J. Found. Comput. Sci. 3 http://dx.doi.org/10.1142/S0129054105003108 db/journals/ijfcs/ijfcs16.html#GeserHWZ05