APA (7th ed.) Citation

Whitney, N. (1998). Open doors 1A: Student's book + workbook. Oxford University Press.

Chicago Style (17th ed.) Citation

Whitney, Norman. Open Doors 1A: Student's Book + Workbook. New York: Oxford University Press, 1998.

MLA (9th ed.) Citation

Whitney, Norman. Open Doors 1A: Student's Book + Workbook. Oxford University Press, 1998.