Transformational Grammar and Transformational Parsing in the Request System. - Warren J. Plath (COLING, 1973)

REQUEST: A Natural Language Question-Answering System. - Warren J. Plath (IBM J. Res. Dev., 1976)

Transformational question-answering (TQA) system: IBM, Yorktown Heights. - Fred J. Damerau; Stanley R. Petrick; M. Pivovonsky; Warren J. Plath (SIGART Newsl., 1982)