REMOVE

1. sky
2. soil
3. roads
4. doors
5. plants
6. barns

WHAT

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