This is good book:
https://www.amazon.com/Stretching-Pocket-Book-Bob-Anderson/d...
This strap is really helpful:
https://www.amazon.com/gp/product/B00065X222/
This is good book:
https://www.amazon.com/Stretching-Pocket-Book-Bob-Anderson/d...
This strap is really helpful:
https://www.amazon.com/gp/product/B00065X222/