Hadfield, S. (2012). Brilliant positive thinking: Transform your outlook and face the future with confidence and optimism. Prentice Hall.
Chicago-referens (17:e uppl.)Hadfield, Sue. Brilliant Positive Thinking: Transform Your Outlook and Face the Future with Confidence and Optimism. Harlow ; New York: Prentice Hall, 2012.
MLA-referens (8:e uppl.)Hadfield, Sue. Brilliant Positive Thinking: Transform Your Outlook and Face the Future with Confidence and Optimism. Prentice Hall, 2012.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.