Walker, E., & Nguyễn Văn Phước. (2003). Grammar practice for Pre- intermadiate student's. Trẻ.
Παραπομπή Chicago StyleWalker, Elaine., και Nguyễn Văn Phước. Grammar Practice for Pre- Intermadiate Student's. Trẻ, 2003.
Παραπομπή MLAWalker, Elaine., και Nguyễn Văn Phước. Grammar Practice for Pre- Intermadiate Student's. Trẻ, 2003.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.