MLA

Thayer, Scofield, 1889-1982. Orr, Elaine: letters from Scofield Thayer. Box 79, folder 2029-2056. 1916 May 26-1918 June 14. https://collections.library.yale.edu/catalog/17142347.

APA, 6th edition

Thayer, Scofield, 1889-1982. (["Box 79, folder 2029-2056"])(1916 May 26-1918 June 14)[Orr, Elaine: letters from Scofield Thayer]. https://collections.library.yale.edu/catalog/17142347.