APA Style
Krashen, Stephen D. (1987).
Principles and practice in second language acquisition .
Singapura:
Practice-Hall International.
Chicago Style
Krashen, Stephen D.
Principles and practice in second language acquisition.
Singapura:
Practice-Hall International,
1987.
Text.
MLA Style
Krashen, Stephen D.
Principles and practice in second language acquisition.
Singapura:
Practice-Hall International,
1987.
Text.
Turabian Style
Krashen, Stephen D.
Principles and practice in second language acquisition.
Singapura:
Practice-Hall International,
1987.
Print.