REMOVE

1. sky
2. railroads
3. machinery
4. clouds
5. hills
6. barriers
7. paths
8. black-and-white film

WHAT

1. Visual Works (hierarchy n … (1)
2. artists (visual artists) (1)
3. beards (1)
4. berets (1)

More 

WHERE

1. New Windsor, Maryland (1)

WHO

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

WHEN

1. 1971 (1)