During an argument about using metric terms, Mallory Archer says, "Who are you, Thomas Corwin Mendenhall?" Thomas Corwin Mendenhall (d. 1924) was an American physicist and meteorologist who advocated for the adoption of the metric system by the United States.
Archer's response ("I learned it by watching you!") to Malory's scolding him over eating the cocaine/yogurt is a reference to the 1980s anti-drug public service announcement "Parents Who Use Drugs".
When Archer says "Said Ripley to the android bishop.", it refers to the British saying "said the actress to the bishop", which is intended to suggest a double entendre just like "phrasing" did in early episodes. The North American equivalent is "that's what SHE said!"
When Agent Holly tries to break down a door, he asks, "What is this door made out of, mithril?" Mithril is a fictional metal found in the writings of J.R.R. Tolkien, where it's described as being stronger than steel.
When Archer and Lana are in the kitchen discussing porn, Archer confesses he has Minitel. Minitel was a French videotex service that was the most popular online service prior to the World Wide Web.