Do you know where can one find more details about this book written by A.Dunnington? I didn't find any reviews about this book (it is old enough, but there are not many books on the Reti).
There are far more recent books on the Reti than that relic.
Chess Stars published a book 5 to 10 years ago.
Thinkers Press published the Modernized Reti a couple of years ago.
There are others as well which can be found at sites with greater selection, like USCFSales.com, who ships world wide.
Also, do not forget that the Reti cannot be played as a standalone system.
The Reti is dependent on Black playing 1...d5 (or 1...Nf6 with an early d5 somewhere). If 1...c5 (or 1...Nf6 and 2...c5), you are looking at an English, not a Reti, and if 1...Nf6 and 2...g6, usually White gets nothing without d4 played, leading to the Kings Indian Defense (Though the Grunfeld can be avoided with this move order).
So you need not only a system in the Reti, but also the Symmetrical English (you do avoid the 1...e5 lines this way) and then something against the Kings Indian.
Do you know where can one find more details about this book written by A.Dunnington? I didn't find any reviews about this book (it is old enough, but there are not many books on the Reti).