REMOVE

1. hills
2. clouds
3. houses
4. trees
5. roads
6. 1936

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)

More 

WHO

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

WHEN

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