APA (7th ed.) Citation

Xavier Sáez-Llorens & Javier Nieto Guevara. Cartas. Pan American Health Organization.

Chicago Style (17th ed.) Citation

Xavier Sáez-Llorens and Javier Nieto Guevara. Cartas. Pan American Health Organization.

MLA (9th ed.) Citation

Xavier Sáez-Llorens and Javier Nieto Guevara. Cartas. Pan American Health Organization.

Warning: These citations may not always be 100% accurate.