Martha E. Pollack Julia Hirschberg Bonnie L. Webber User Participation in the Reasoning Processes of Expert Systems. 358-361 1982 conf/aaai/1982 AAAI db/conf/aaai/aaai82.html#PollackHW82 http://www.aaai.org/Library/AAAI/1982/aaai82-085.php