REMOVE

1. hills
2. roads
3. trucks
4. sky

WHAT

1. black-and-white film (1)
2. clouds (1)
3. fields (land) (1)
4. horizon line (1)
5. landscapes (representatio … (1)
6. plants (1)
7. silhouettes (1)
8. soil (1)
9. sunlight (1)
10. trees (1)
11. Visual Works (hierarchy n … (1)
12. 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)