APA (7th ed.) Citation

Helgren, D. M., Sager, R. J., & Israel, S. (1985). World geography today: Teacher's resource. Holt, Rinehart and Winston.

Chicago Style (17th ed.) Citation

Helgren, David M., Robert J. Sager, and Saul Israel. World Geography Today: Teacher's Resource. Holt, Rinehart and Winston, 1985.

MLA (8th ed.) Citation

Helgren, David M., et al. World Geography Today: Teacher's Resource. Holt, Rinehart and Winston, 1985.