APA
Nuttall C. (. &. S. B., . (1970). Question-tags Unit 17. Longmans, London: .
Chicago
Nuttall C.E (Ed) & Susilvorn B.J, . 1970. Question-tags Unit 17. Longmans, London: .
Harvard
Nuttall C. (. &. S. B., . (1970). Question-tags Unit 17. Longmans, London: .
MLA
Nuttall C.E (Ed) & Susilvorn B.J, . Question-tags Unit 17. Longmans, London: . 1970.