Alan W. Biermann Curry I. Guinn Michael S. Fulkerson Greg A. Keim Zheng Liang Douglas M. Melamed Krishnan Rajagopalan Goal-Oriented Multimedia Dialogue with Variable Initiative. 1-16 1997 conf/ismis/1997 ISMIS db/conf/ismis/ismis97.html#BiermannGFKLMR97 http://dx.doi.org/10.1007/3-540-63614-5_1