MLA

Korvin-Piotrovskiĭ, Vladimir Lʹvovich, 1891-1966. Peyron, Guido. Box 11, folder 238. 1920s-1930s. https://collections.library.yale.edu/catalog/16601476.

APA, 6th edition

Korvin-Piotrovskiĭ, Vladimir Lʹvovich, 1891-1966. (["Box 11, folder 238"])(1920s-1930s)[Peyron, Guido]. https://collections.library.yale.edu/catalog/16601476.