STACK ROUTINE:the shelves assistant Available to Purchase

AS FAR AS I know very few libraries have a designated post of Shelves Assistant. Firstly, it is necessary for there to be a reference library of ancient vintage and of considerable size, say, upwards of half a million items. Secondly, the library building must be near to the end of its available shelf space but with little prospect of getting an extension or a new building for ten or twenty years.