There is a whole host of BBC micro and 6502 related books here. Many of them relate to hardware or software such as Wordwise, the Watford Electronics ROM Board and so on. There is a copy of the Advanced User Guide in the top-right hand corner of the picture. This is one of the best books ever written for the BBC micro.

There are a couple of interesting items here from Acorn which I have never seen before. One is the BASIC II user guide which is a thin green-backed pamphlet describing the differences between BASIC I and BASIC II. The other is the Master 128 System ROM User Guide which is another short publication which describes the differences between MOS 3.20 and MOS 3.50.