REMOVE

1. workers
2. sky
3. rock
4. hills
5. utility poles
6. boys

WHAT

1. art criticism (1)
2. art galleries (institutio … (2)
3. art schools (institutions … (2)
4. artists (visual artists) (2)
5. exhibitions (events) (2)
6. graphite (1)
7. Information Forms (hierar … (2)
8. ink (2)
9. paintings (visual works) (2)
10. students (1)
11. testimonials (2)
12. viewers (observers) (2)

Less

WHERE

1. San Francisco, California (1)

WHEN

1. 1950 (2)