Luis A. Castillo Juan Fernández-Olivares Óscar García-Pérez Francisco Palao Efficiently Handling Temporal Knowledge in an HTN Planner. 63-72 2006 conf/aips/2006 ICAPS db/conf/aips/icaps2006.html#CastilloFGP06 http://www.aaai.org/Library/ICAPS/2006/icaps06-007.php