Lockley, S. W. (2012). Sleep: A Very Short Introduction (1st.). Oxford.
Cita Chicago (17th ed.)Lockley, Steven W. Sleep: A Very Short Introduction. 1st. Oxford, 2012.
Cita MLA (9th ed.)Lockley, Steven W. Sleep: A Very Short Introduction. 1st. Oxford, 2012.
Atenció: Aquestes cites poden no estar 100% correctes.