REMOVE

1. rubbish
2. workers
3. soil
4. sky
5. Pittsburgh, Pennsylvania

WHAT

1. Visual Works (hierarchy n … (1)
2. artists (visual artists) (1)
3. barriers (1)
4. black-and-white film (1)
5. bushes (1)

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WHERE

1. Westminster, Maryland (1)

WHO

1. Campbell, Sandra L. Still (1)
2. Sandra L. Still Campbell; … (1)

WHEN

1. 1964 (1)