REMOVE

1. machinery
2. hills
3. tools
4. landscapes (representations)
5. black-and-white film

WHAT

1. cornstalk (2)
2. cranes (equipment) (2)
3. fields (land) (2)
4. freight cars (2)
5. hats (2)
6. men (male humans) (2)
7. plants (2)
8. railroads (2)
9. rails (transit system ele … (2)
10. rubbish (2)
11. sky (2)
12. soil (2)
13. tractors (agricultural eq … (2)
14. trains (vehicle groupings … (2)
15. trees (2)
16. trucks (2)
17. utility poles (2)
18. Visual Works (hierarchy n … (2)
19. woods (plant communities) (2)
20. workers (2)

WHERE

1. New Windsor, Maryland (2)

WHO

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

More 

WHEN

1. 1969 (2)