APA način citiranja (7. izdanje)

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

Čikaški stil citiranja (17. izdanje)

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

MLA način citiranja (9. izdanje)

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