HК 007, Heinrich Klassen, Piano pieces (30 easy, mediumdifficult and difficult pieces for piano solo and four-handed incl. CD)
HК 003, Heinrich Klassen, Musical sketches (Romantic, medium difficult pieces for piano solo) Book 1, No. 1-11
HК 006, Heinrich Klassen, Musical sketches (Romantic, medium difficult pieces for piano solo) Book 2, No. 12-25
HК 004, Heinrich Klassen, Scale? No problem! (Piano exercises, scales, chords and arpeggios for beginners and advanced) English