MLA

Korvin-Piotrovskiĭ, Vladimir Lʹvovich, 1891-1966. Illegible signatures. Box 11, folder 248. 1912-1950, undatd. https://collections.library.yale.edu/catalog/17278865.

APA, 6th edition

Korvin-Piotrovskiĭ, Vladimir Lʹvovich, 1891-1966. (["Box 11, folder 248"])(1912-1950, undatd)[Illegible signatures]. https://collections.library.yale.edu/catalog/17278865.