APA (7th ed.) Citation
Watkins, F., & Hiers, J. (1989). Practical English workbook (4th ed.). Houghton.
Chicago Style (17th ed.) Citation
Watkins, Floyd, and John Hiers. Practical English Workbook. 4th ed. Boston: Houghton, 1989.
MLA (9th ed.) Citation
Watkins, Floyd, and John Hiers. Practical English Workbook. 4th ed. Houghton, 1989.
Warning: These citations may not always be 100% accurate.