I've learned that this may well have to do with the country from which your computer is accessing the web. When you access material, your ip address indicates country of origin, if there are copyright issues on the available works in your country, either you draw a blank or limited viewing. However, my understanding of this rather vague, and your own computer settings may have some effect.
Why not get a poll going and compare viewability.
I've just checked and have full view of all 19 books. (NY, USA)
Patrick, can you double check US access?
Trev & Carling, can you let us know about England?
Doos, the Netherlands please?
The rest of the world, please don't be shy, let us know what is available to you and what is not.
Appreciate the help.