- Электронная книгаThe First Studies for Every Piano Student as the Technical Foundation for VirtuosityLouis Köhler
- Электронная книгаKöhler - The Easiest Exercise Pieces for piano Op.190Louis Köhler
- Электронная книгаKöhler - Little School of Piano Velocity Op.242Louis Köhler
- Электронная книгаKöhler - New School of Velocity for Piano Op.128Louis Köhler