Prior Research https://serc.carleton.edu/spatialworkbook/prior_research.html
Provenance This image or file is a work of a Defense Advanced Research Projects Agency (DARPA), an agency of the United States Department of Defense, employee, taken or made during the course of an employee's official duties. As a work of the U.S. federal government, the image is in the public domain. Available via Wikimedia Commons: http://commons.wikimedia.org/wiki/File:Chemical_compound_being_drawn.jpg
Reuse This item is in the public domain
and maybe reused freely without restriction.