APA
Ward A., Whitney N., . (1996). Open doors. workbook 2. Oxford: Oxford University Press.
Chicago
Ward Ann, Whitney Norman, . 1996. Open doors. workbook 2. Oxford: Oxford University Press.
Harvard
Ward A., Whitney N., . (1996). Open doors. workbook 2. Oxford: Oxford University Press.
MLA
Ward Ann, Whitney Norman, . Open doors. workbook 2. Oxford: Oxford University Press. 1996.