MLA

Ochoa Carrillo, Antonio, 1811-1883. Juárez, Benito. Autograph letter, signed: Chihuahua, to Antonio Ochoa Carrillo.. Box 1, folder 66. 1866 November 20. https://collections.library.yale.edu/catalog/32320169.

APA, 6th edition

Ochoa Carrillo, Antonio, 1811-1883. (["Box 1, folder 66"])(1866 November 20)[Juárez, Benito. Autograph letter, signed: Chihuahua, to Antonio Ochoa Carrillo.]. https://collections.library.yale.edu/catalog/32320169.