APA Style

Royston, Angela, Davidson, Chris. (2009). Why Do I Sleep? . London: QED Publishing.

Chicago Style

Royston, Angela, Davidson, Chris. Why Do I Sleep?. London: QED Publishing, 2009. Text.

MLA Style

Royston, Angela, Davidson, Chris. Why Do I Sleep?. London: QED Publishing, 2009. Text.

Turabian Style

Royston, Angela, Davidson, Chris. Why Do I Sleep?. London: QED Publishing, 2009. Print.