The books were produced by Trainers Records Publications of Bridport.
With the coming of the internet, there's no longer a market for such book, as all of the statistics are freely available online (which also means that they can be kept far more up to date than was possible in print publications). e.g. here on the Sky Sports website:
https://www.skysports.com/racing/statistics/flat-trainers/season
(Click on a trainer's name for full details of the horses he's had entered for races, together with the names of the jockeys riding them).