L. Lucignano, F. Cutugno, S. Rossi, and A. Finzi. Proceedings of the 15th ACM on International Conference on Multimodal Interaction, page 197–204. New York, NY, USA, Association for Computing Machinery, (2013)
H. Geffner, and B. Bonet. Proceedings AIPS-98 Workshop on Integrating Planning, Scheduling and Execution in Dynamic and Uncertain Environments., (1998)