REMOVE

1. barriers
2. plants
3. sunlight
4. trees
5. rooftops
6. 1967

WHAT

1. Visual Works (hierarchy n … (1)
2. artists (visual artists) (1)
3. beards (1)
4. black-and-white film (1)
5. branches (plant component … (1)

More 

WHERE

1. New Windsor, Maryland (1)

WHO

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

WHEN

1. 1972 (1)