Translation: Piano Method sheet music. Piano Solo sheet music. Edited by Ruthardt. For piano. Sheet Music. Published by Edition Peters. PE.P03521.
Translation: 20 Early studies Op. 50. 20 Early studies Op. 50 composed by Louis H. Kohler. Piano Solo sheet music.
Translation: Gurlitt Op.50 no. 5, Op.83 no. Kohler Op.190 no. 33, Op.249 no. Le Couppey Op.17 no.
