Gretchen's baby is called Homer Jr., nicknamed "HoJu" by Homer. In Marge vs. the Monorail (1993), Homer asks Bart if would like to change his name to Homer Jr. after he tells his father that he wants to be just like him, and that "the kids can call you HoJu".
In the elevator, there is a sign with technical information, including "State ID#: RABF19". This also happens to be the production code of this episode.
Cheerleaders' posters writes: "Meltdown", "Raise your core temperature" and "Cheernobyl".
Chalkboard gag: "Rocktober is not followed by blowvember"
Springfield Shopper headlines: "Tire fire turns 20", "Local man tries golf, doesn't like it", "Apple buys Facebook on Ebay" and "Newspaper can't afford articles on back".