REMOVE

1. sky
2. trees
3. houses
4. barriers
5. portraits
6. men (male humans)

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)