APA (7th ed.) Citation

Harris, Mower, & Sikorzynþska. (2004). Opportunities: Elementary (12th impression.). Longman.

Chicago Style (17th ed.) Citation

Harris, Mower, and Sikorzynþska. Opportunities: Elementary. 12th impression. Harlow: Longman, 2004.

MLA (8th ed.) Citation

Harris, et al. Opportunities: Elementary. 12th impression. Longman, 2004.