APA (7th ed.) Citation

Greenall, S., & Garton-Sprenger, J. Horizons. Students' book.

Chicago Style (17th ed.) Citation

Greenall, Simon, and Judy Garton-Sprenger. Horizons. Students' Book.

MLA (8th ed.) Citation

Greenall, Simon, and Judy Garton-Sprenger. Horizons. Students' Book.

Warning: These citations may not always be 100% accurate.