MLA

Hollander, John, 1929-2013. Heaney, Seamus. Box 3. 1994 March 25. https://collections.library.yale.edu/catalog/17210413.

APA, 6th edition

Hollander, John, 1929-2013. (["Box 3"])(1994 March 25)[Heaney, Seamus]. https://collections.library.yale.edu/catalog/17210413.