REMOVE

1. roads
2. erosion
3. soil
4. exterior views

WHAT

1. Visual Works (hierarchy n … (1)
2. arbors (1)
3. artists (visual artists) (1)
4. atmospheric perspective (1)
5. automobiles (1)

More 

WHERE

1. Westminster, Maryland (1)

WHO

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

Less

WHEN

1. 1961 (1)
2. 1965 (1)
3. between 1961 - 1965 (1)