Wierd-sisters [sic], minister's of darkness, minions of the moon [graphic].
MLA
Gillray, James, 1756-1815, printmaker. http://id.loc.gov/authorities/names/n50033402. Wierd-sisters [sic], minister's of darkness, minions of the moon [graphic].. 1791 December 23. https://collections.library.yale.edu/catalog/11811301.
APA, 6th edition
Gillray, James, 1756-1815, printmaker. http://id.loc.gov/authorities/names/n50033402. (1791 December 23)[Wierd-sisters [sic], minister's of darkness, minions of the moon [graphic].]. https://collections.library.yale.edu/catalog/11811301.