REMOVE

1. rubbish
2. soil
3. trees
4. sky
5. houses
6. freight cars

WHAT

1. Visual Works (hierarchy n … (1)
2. artists (visual artists) (1)
3. black-and-white film (1)
4. collectors (1)
5. doorways (1)

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WHERE

1. Los Angeles, California (1)

WHEN

1. 1961 (1)