APA (7th ed.) Zitazioa

Roldan, C. A. (2005). The ultimate echo guide. Lippincott Williams & Wilkins.

Chicago Style (17th ed.) Zitazioa

Roldan, Carlos A. The Ultimate Echo Guide. Philadelphia: Lippincott Williams & Wilkins, 2005.

MLA (9th ed.) Zitazioa

Roldan, Carlos A. The Ultimate Echo Guide. Lippincott Williams & Wilkins, 2005.