REMOVE

1. plants
2. automobiles
3. workers
4. branches (plant components)
5. wheels (components)

WHAT

1. Visual Works (hierarchy n … (3)
2. exterior views (3)
3. houses (3)
4. lamps (lighting devices) (3)

More 

WHERE

1. New Windsor, Maryland (3)

WHO

1. Campbell, Sandra L. Still (1)
2. Clyfford Still; Still, Cl … (1)
3. Sandra L. Still Campbell; … (1)
4. Still, Clyfford (1)

Less

WHEN

1. 1966 (2)
2. after 1966 (2)
3. 1969 (1)