This television episode refers to:
August 25, 1939
When Bart wakes up from his out-of-body experience, he says, "I did go away, Mom! I was miles and miles and miles away, writhing in agony in the pits of Hell! And you were there! And you and you and you," a reference to the 1939 film adaptation of The Wizard of Oz, when Dorothy awakens from her slumber.