Sheet of stamps commemorating the 1962 Seattle World's Fair

Chicago citation style
Unknown. Sheet of stamps commemorating the 1962 Seattle World's Fair. 1962. Retrieved from the Digital Public Library of America, http://cdm16786.contentdm.oclc.org/cdm/ref/collection/ptec/id/3706. (Accessed June 22, 2018.)
APA citation style
Unknown, (1962) Sheet of stamps commemorating the 1962 Seattle World's Fair. Retrieved from the Digital Public Library of America, http://cdm16786.contentdm.oclc.org/cdm/ref/collection/ptec/id/3706
MLA citation style
Unknown. Retrieved from the Digital Public Library of America <http://cdm16786.contentdm.oclc.org/cdm/ref/collection/ptec/id/3706>.
Note: These citations are programmatically generated and may be incomplete.