Walker, E., & Nguyễn Văn Phước. (2003). Grammar practice for Pre- intermadiate student's. Trẻ.
Chicago Style aipamenaWalker, Elaine., và Nguyễn Văn Phước. Grammar Practice for Pre- Intermadiate Student's. Trẻ, 2003.
MLA aipamenaWalker, Elaine., và Nguyễn Văn Phước. Grammar Practice for Pre- Intermadiate Student's. Trẻ, 2003.
Kontuz: berrikusi erreferentzia hauek erabili aurretik.