In every Look Back, we examine a comic book issue from 10/25/50/75 years ago (plus a wild card every month with a fifth week in it). This time around, since this is a five-week month, we head back thirty years to December 1993, for the reveal of Harley Quinn's origin in The Batman Adventures: Mad Love.
Source:https://www.cbr.com/harley-quinn-origin-revealed-thirty-years-ago/