Freeman, D. You Can Be Happy: The Scientifically Proven Way to Change How You Feel (1.). Pearson Education UK.
Chicago-referens (17:e uppl.)Freeman, Daniel;Freeman. You Can Be Happy: The Scientifically Proven Way to Change How You Feel. 1. Pearson Education UK.
MLA-referens (8:e uppl.)Freeman, Daniel;Freeman. You Can Be Happy: The Scientifically Proven Way to Change How You Feel. 1. Pearson Education UK.
Varning: dessa hänvisningar är inte alltid fullständigt riktiga.