REMOVE

1. replicas
2. landscapes (representations)
3. fields (land)

WHAT

1. Visual works (hierarchy n … (1)
2. barbed wire (1)
3. bone (material) (1)
4. clouds (1)
5. fences (site elements) (1)

More 

WHERE

1. Pullman, Washington (1)

WHO

1. Still, Clyfford (1)

WHEN

1. 1938 (1)