REMOVE

1. boys
2. automobiles
3. plants
4. backdrops
5. artists (visual artists)
6. barriers

WHAT

1. Visual Works (hierarchy n … (1)
2. benches (furniture) (1)
3. black-and-white film (1)

More 

WHERE

1. New York, New York (1)

WHO

1. Diane Still Knox; Diane K … (1)
2. Knox, Diane Still (1)

WHEN

1. 1958 (1)