REMOVE

1. barns
2. lamps (lighting devices)
3. concrete block
4. snow (precipitation)

WHAT

1. Visual Works (hierarchy n … (1)
2. barriers (1)
3. black-and-white film (1)
4. buildings (structures) (1)

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WHO

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

WHEN

1. 1961 (1)
2. after 1961 (1)