Cite

3 sheets of Polish postage stamps featuring cats

MLA

3 Sheets of Polish Postage Stamps Featuring Cats. 0AD. https://collections.library.yale.edu/catalog/2112228.

APA, 6th edition

3 sheets of Polish postage stamps featuring cats. (0 C.E.). [Ephemera, Postage stamps]. https://collections.library.yale.edu/catalog/2112228.