Marc Helgesen. (1998). Travel File (Teacher's manual). London: Longman.
Trích dẫn kiểu ChicagoMarc Helgesen. Travel File (Teacher's Manual). London: Longman, 1998.
MLA引文Marc Helgesen. Travel File (Teacher's Manual). London: Longman, 1998.
警告:這些引文格式不一定是100%准確.