REMOVE

1. plants
2. rock
3. fences
4. sky

WHAT

1. Visual Works (hierarchy n … (2)
2. buildings (structures) (2)
3. exterior views (2)
4. fields (land) (2)
5. forests (plant communitie … (2)

More 

WHERE

1. New Windsor, Maryland (1)
2. Westminster, Maryland (1)

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. 1969 (1)
2. 1975 (1)