Download summer silhouettes in vector art format. Free summer fun design theme with friends jumping for joy, colorful radiant vector background and “Enjoy the fun” message. Celebrate the sunny days of summer with this happy and energetic vector silhouettes design pack.
This is clipart converted and broken apart that has been released into the public domain because the document says so, and its from NASA, a USA government agency. The publication is called "The Brain in Space:"
http://www.nasa.gov/audience/foreducators/topnav/materials/listbytype/The.Brain.in.Space.html