MLA

Robinson, Mary, fl. 1802. Fifty pounds reward. Notorious impostor, swindler & felon, John Hatfield, who lately married to the Beauty of Buttermere [i.e. Mary Robinson] under an assumed name. [1802?].. https://collections.library.yale.edu/catalog/2012105.

APA, 6th edition

Robinson, Mary, fl. 1802. ([1802?].)[Fifty pounds reward. Notorious impostor, swindler & felon, John Hatfield, who lately married to the Beauty of Buttermere [i.e. Mary Robinson] under an assumed name]. https://collections.library.yale.edu/catalog/2012105.