REMOVE

1. trees
2. artists (visual artists)
3. Niagara Falls, Ontario, Cana …

WHAT

1. Niagara Falls (waterfall) (1)
2. Visual Works (hierarchy n … (1)
3. black-and-white film (1)
4. eyeglasses (1)

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WHO

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

WHEN

1. 1964 (1)