REMOVE

1. trees
2. houses
3. clouds
4. silhouettes
5. landscapes (representations)
6. roads

WHAT

1. Visual Works (hierarchy n … (1)
2. artists (visual artists) (1)
3. barns (1)
4. benches (furniture) (1)
5. 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)