APA citiranje

Helgren, D. M., & Sager, R. J. (1995). World geography today. Holt, Rinehart and Winston.

Chicago Style (17th ed.) Citation

Helgren, David M., and Robert J. Sager. World Geography Today. Austin, TX: Holt, Rinehart and Winston, 1995.

MLA citiranje

Helgren, David M., and Robert J. Sager. World Geography Today. Holt, Rinehart and Winston, 1995.