MLA

Ochoa Carrillo, Antonio, 1811-1883. Juárez, Benito. Autograph letter, signed: Chihuahua, to Antonio Ochoa Carrillo. Box 1, folder 58. 1866 July 31. https://collections.library.yale.edu/catalog/32320081.

APA, 6th edition

Ochoa Carrillo, Antonio, 1811-1883. (["Box 1, folder 58"])(1866 July 31)[Juárez, Benito. Autograph letter, signed: Chihuahua, to Antonio Ochoa Carrillo]. https://collections.library.yale.edu/catalog/32320081.