When Barney goes up to Jerry on the dance floor to suggest he stop dancing, Jerry (played by John Lithgow) says "Sorry, small town preacher from the mid-west, is there a law against dancing?". This is an inside joke reference to the movie Footloose (1984), which portrays a small mid-west town where dancing has been outlawed for moral reasons, a movement spearheaded by the town preacher, played by John Lithgow.
When Marshall is talking about his playwright "works" he mentions a rock opera. This is reference to Jason Segel's rock opera in Forgetting Sarah Marshall.
The shirt that Robin's crush (Nick) is wearing in the flash back of the close out sale is the same shirt that one of the GCWOK's was wearing in Season 3, Episode 19 "Everything Just Go"
The episode starts with a flashback to Jerry & Barney in 1983, but in S6, E8, Natural History, the incident report of Barney knocking down the whale took place on July 23rd 1981 & Barney tells Robin that was the last time he ever saw Jerry.