Idzikowski,Christophe. Sound asleep: The expert guide to sleeping well. Watkins Publishing.
Cita Chicago (17th ed.)Idzikowski,Christophe. Sound Asleep: The Expert Guide to Sleeping Well. Watkins Publishing.
Cita MLA (8th ed.)Idzikowski,Christophe. Sound Asleep: The Expert Guide to Sleeping Well. Watkins Publishing.
Atenció: Aquestes cites poden no estar 100% correctes.