Johan Boye Mats Wirén Manny Rayner Ian Lewin David M. Carter Ralph Becket Language-Processing Strategies and Mixed-Initiative Dialogues. 73-88 1999 3 Electron. Trans. Artif. Intell. D http://www.ep.liu.se/ea/cis/1999/024/ db/journals/etai/etai3.html#BoyeWRLCB99