A simple picture abstracting a flock of flying birds. Mad from a very simple object of 3 circles (wings are just stretched and skewed). Then copies made and different effects using tweak tool.
This image was donated by Pearson Scott Foresman, an educational publisher, to Wikimedia Commons, and is thereby in the Public Domain.
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See http://commons.wikimedia.org/wiki/Category:Pearson_Scott_Foresman_publisher