MLA

Davies, W. H. (William Henry), 1871-1940. Letters : Sevenoaks, England, to Edward Thomas. Box 102, folder Group 106, V-1. 1908-11. https://collections.library.yale.edu/catalog/2044478.

APA, 6th edition

Davies, W. H. (William Henry), 1871-1940. (["Box 102, folder Group 106, V-1"])(1908-11)[Letters : Sevenoaks, England, to Edward Thomas]. https://collections.library.yale.edu/catalog/2044478.