Hasson, G. (2017). Positive thinking: Find happiness and achieve your goals through the power of positive thought. Capstone, A Wiley Brand.
Chicago-viite (17. p.)Hasson, Gill. Positive Thinking: Find Happiness and Achieve Your Goals Through the Power of Positive Thought. Chichester, West Sussex, UK: Capstone, A Wiley Brand, 2017.
MLA-viite (9. p.)Hasson, Gill. Positive Thinking: Find Happiness and Achieve Your Goals Through the Power of Positive Thought. Capstone, A Wiley Brand, 2017.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.