Gaya APA
Shepherd, P. (2021).
The Positive Approach : Manfaat Berpikir & Bersikap Positif .
yogyakarta:
Bright Publisher.
Gaya MLA
Shepherd, Peter.
"The Positive Approach : Manfaat Berpikir & Bersikap Positif".
yogyakarta:
Bright Publisher,
2021.
Text.