REMOVE

1. hills
2. rivers
3. barriers
4. plants
5. 1977

WHAT

1. Visual Works (hierarchy n … (1)
2. black-and-white film (1)
3. farms (1)
4. fences (1)
5. fields (land) (1)

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WHO

1. Clyfford Still; Still, Cl … (1)
2. Still, Clyfford (1)

WHEN

1. 1920 (1)
2. 1940 (1)
3. between 1920 - 1940 (1)