U.S. National Library of Medicine's Digital Collections
"Digital Collections is the National Library of Medicine's free online repository of biomedical resources including books, still images, videos, and maps. All of the content in Digital Collections is freely available worldwide and, unless otherwise indicated, in the public domain."
Image: National Institutes of Health (U.S.). Medical Arts and Photography Branch. (1989). Health communications in español. Retrieved from http://resource.nlm.nih.gov/101454128