Button, University of Pennsylvania, round with lettering 'PENNA'

Chicago citation style
Button, University of Pennsylvania, round with lettering 'PENNA'. 19uu. Retrieved from the Digital Public Library of America, http://dla.library.upenn.edu/dla/archives/image.html?id=ARCHIVES_20060518012. (Accessed December 17, 2018.)
APA citation style
(19uu) Button, University of Pennsylvania, round with lettering 'PENNA'. Retrieved from the Digital Public Library of America, http://dla.library.upenn.edu/dla/archives/image.html?id=ARCHIVES_20060518012
MLA citation style
Retrieved from the Digital Public Library of America <http://dla.library.upenn.edu/dla/archives/image.html?id=ARCHIVES_20060518012>.
Note: These citations are programmatically generated and may be incomplete.