There are 8 different exercises/disciplines, book format works because you can leave the book open on a table while you do them and having nice big pictures is good.

Try it out, if it doesn't work you've wasted a mere 20 pounds/dollars/euros. If it does you'll have a pain free back, pretty good risk/reward payoff.

It has worked for me and millions of others.

Good luck :-)

Cg