MLA

Pearson, Norman Holmes, 1909-1975. Bunting, Basil. Box 25. 1953 October 29. https://collections.library.yale.edu/catalog/17260073.

APA, 6th edition

Pearson, Norman Holmes, 1909-1975. (["Box 25"])(1953 October 29)[Bunting, Basil]. https://collections.library.yale.edu/catalog/17260073.