Cita APA (7th ed.)
Roldan, C. A. (2005). The ultimate echo guide. Lippincott Williams & Wilkins.
Cita Chicago (17th ed.)
Roldan, Carlos A. The Ultimate Echo Guide. Philadelphia: Lippincott Williams & Wilkins, 2005.
Cita MLA (9th ed.)
Roldan, Carlos A. The Ultimate Echo Guide. Lippincott Williams & Wilkins, 2005.
Atenció: Aquestes cites poden no estar 100% correctes.