 In the scene where Pastrami and Asthma have the professors hostage  in the library, the gunmen begin shooting at random items. One  gunman (Pastrami) says something like, "I saw this in a movie," and  proceeds to lick his thumb and then rubs it on the sight of his gun.  This is a reference to star Gary Cooper (I) (qv)s previous movie  _Sergeant York (1941)_ (qv) in which York uses this as a technique  to improve his marksmanship.