Cita APA (7th ed.)

Day, J. C. (1990). PFS:First choice: Workbook and user's guide. Harper Collins.

Cita Chicago (17th ed.)

Day, John C. PFS:First Choice: Workbook and User's Guide. New York: Harper Collins, 1990.

Cita MLA (9th ed.)

Day, John C. PFS:First Choice: Workbook and User's Guide. Harper Collins, 1990.