Quotron

Kurt Wurlitzer was engaged on a massive construction project on Quotron when his son Jason was kidnapped and held for ransom. The Second Doctor arrived on Jason's rocket-plane at the Wurlitzer Construction site to deliver the ransom note from the dwarfs, and there agreed to lead a rescue mission to save him. (COMIC: Operation Wurlitzer)

The Quotron's also feature in the comic story U.F.O.