REMOVE

1. boys
2. hats
3. soil
4. buildings (structures)
5. roads
6. trains (vehicle groupings)

WHAT

1. Visual Works (hierarchy n … (1)
2. automobiles (1)
3. banks (landforms) (1)
4. black-and-white film (1)

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WHERE

1. New Windsor, Maryland (1)

WHO

1. Campbell, Sandra L. Still (1)
2. Clyfford Still; Still, Cl … (1)
3. Sandra L. Still Campbell; … (1)
4. Still, Clyfford (1)

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WHEN

1. 1969 (1)