Gaya APA
Lou, R. (2007).
Toefl common errors and grammar practice: the book that makes you score higher/ Robby Lou .
Jakarta:
E Plus Mobile English.
Gaya MLA
Lou, Robby.
"Toefl common errors and grammar practice: the book that makes you score higher/ Robby Lou".
Jakarta:
E Plus Mobile English,
2007.
Text.