REMOVE

1. Spain
2. ink
3. Basel, Switzerland
4. Westminster, Maryland
5. Paris, France

WHAT

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

More 

WHO

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

WHEN

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