REMOVE

1. utility poles
2. sidewalks
3. shadows
4. sky
5. streets
6. campuses
7. automobiles

WHAT

1. Visual Works (hierarchy n … (1)
2. buildings (structures) (1)
3. bushes (1)

More 

WHERE

1. San Francisco, California (1)

WHO

1. Clyfford Still; Still, Cl … (1)
2. Still, Clyfford (1)

WHEN

1. 1971 (1)
2. ca. 1971 (1)