Gaya APA
Leedy, P, D., Ellis, J.
(2018).
Practical Research: Planning and Design 12th ed
(
12)
.
New York:
Pearson.
Gaya MLA
Leedy, Paul, D., Ellis, Jeanne.
"Practical Research: Planning and Design 12th ed".
12
New York:
Pearson,
2018.
Printed.