[Notes on Picasso]
MLA
Hartley, Marsden, 1877-1943. [Notes on Picasso]. Box 10. undated. https://collections.library.yale.edu/catalog/16721054.
APA, 6th edition
Hartley, Marsden, 1877-1943. (["Box 10"])(undated)[[Notes on Picasso]]. https://collections.library.yale.edu/catalog/16721054.