REMOVE

1. Portrait photographs
2. Nitrate negatives
3. negative
4. Artists' studios.
5. Library of Congress Prints a …
6. 1869-1942

WHAT

1. Artists' studios. (1)
2. Artists. (1)
3. Nitrate negatives (1)
4. Photographs (1)
5. Portrait photographs (1)

WHO

1. Genthe, Arnold (1)
2. Library of Congress Print … (1)

WHEN

1. 1920 (1)
2. 1942 (1)
3. between 1920 and 1942 (1)