MLA

Gadbury, John, 1627-1704, Lady of quality, Oates, Titus, 1649-1705, Powis, Elizabeth Somerset Herbert, Marchioness of, 1633?-1691. A ballad upon the Popish Plot / Written by a lady of quality ; to the tune of Packington's pound.. 1679?]. https://collections.library.yale.edu/catalog/11378436.

APA, 6th edition

Gadbury, John, 1627-1704, & Lady of quality, & Oates, Titus, 1649-1705, & Powis, Elizabeth Somerset Herbert, Marchioness of, 1633?-1691. (1679?])[A ballad upon the Popish Plot / Written by a lady of quality ; to the tune of Packington's pound.]. https://collections.library.yale.edu/catalog/11378436.