Gaya APA
Usman, A., Lestari, N.
(2017).
The miracle of positive thinking
.
Yogyakarta:
Psikologi Corner.
Gaya MLA
Usman, Asti., Lestari, Nurti.
"The miracle of positive thinking".
Yogyakarta:
Psikologi Corner,
2017.
Text.