REMOVE

1. hills
2. soil
3. sky
4. clouds

WHAT

1. black-and-white film (1)
2. fields (land) (1)
3. horizon line (1)
4. landscapes (representatio … (1)
5. plants (1)
6. silhouettes (1)
7. sunlight (1)
8. trees (1)
9. Visual Works (hierarchy n … (1)
10. woods (plant communities) (1)

WHO

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

WHEN

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