REMOVE

1. trees
2. clouds
3. landscapes (representations)
4. sunlight
5. plants

WHAT

1. black-and-white film (1)
2. fields (land) (1)
3. hills (1)
4. horizon line (1)
5. silhouettes (1)
6. sky (1)
7. soil (1)
8. Visual Works (hierarchy n … (1)
9. 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)