Used Accordion Method Book: How to Play the Club Accordion: A Simple Tutor by A. Holzschuh

"This tutor is a simple instruction book for the club button key accordions and gives the student instruction in the Holzschuh system of notation for these instruments. This system is on the lines of the long-proven principles of notation for this kind of instrument, so that the player is quite able to play music written in similar notations also. The popularity of this tutor has been shown by the fact that several editions have been found necessary, and that experienced teachers of the instrument have welcomed it as providing the student with a quick and yet thorough course in learning to play the accordion." -A. Holzschuh