I got my hands on the E-book of Raising the bar by Al Kavadlo a few days ago. It was absolutely amazing to see the variety of exercises that can be done from just a simple pull up bar. The book demonstrated how to use the Bar to work every different Body part, and simple progressions that can be added to any workout routine. It has a lot photography demonstrating every step of the progressions being done, and the instructions for every exercise was very clear and easy to follow. Even after researching and practicing Calisthenics for so many years I was amazed by how much I gained from this book.