Gaya APA
Shepherd, P. (2021).
The Positive Approach: Manfaat Berpikir dan Bersikap Positif (Cet. v).
liberti,Yogyakarta:
Bright Publisher.
Gaya MLA
Shepherd, Peter.
"The Positive Approach: Manfaat Berpikir dan Bersikap Positif".
Cet. v
liberti,Yogyakarta:
Bright Publisher,
2021.
Textbook.