MLA

Blue Eyed Mary. Published by E. Rushton, Liverpool, August, 1799, and sold by S.W. Fores, No. 50, Piccadilly, London, 1799. https://collections.library.yale.edu/catalog/17124697.

APA, 6th edition

Blue eyed Mary. (1799). [Single sheet verse, Broadside poems, Engravings England Liverpool 1799]. Published by E. Rushton, Liverpool, August, 1799, and sold by S.W. Fores, No. 50, Piccadilly, London. https://collections.library.yale.edu/catalog/17124697.