REMOVE

1. boys
2. daughters
3. windows
4. children
5. buildings (structures)
6. hats

WHAT

1. Visual Works (hierarchy n … (1)
2. automobiles (1)
3. black-and-white film (1)
4. bushes (1)

More 

WHERE

1. Westminster, Maryland (1)

WHO

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

WHEN

1. 1966 (1)
2. ca. 1966 (1)