A Corpus of English Conversation. Edited by Jan Svartvik and Randolph Quirk. Lund Studies in English 56. Lund,Sweden: C. W. L. Gleerup,1980,pp. 893

Bowman, Elizabeth. 1966 The Minor and Fragmentary Sentences in a Corpus of Spoken American English. Indiana University Research Center in Anthropology, Folklore and Linguistics, publication 42. Ph.D. dissertation, University of Chicago , 1964.

Quirk, Randolph ; Greenbaum, Sidney ; Leech, Geoffrey , and Svartvik, Jan. A Grammar of Contemporary English. London: Longman, 1972.