Pietro Abate Rajeev Goré Florian Widmann An On-the-fly Tableau-based Decision Procedure for PDL-satisfiability. 191-209 2009 231 Electr. Notes Theor. Comput. Sci. http://dx.doi.org/10.1016/j.entcs.2009.02.036 db/journals/entcs/entcs231.html#AbateGW09