The first edition of Kröll's portfolio of works 'Tagebuch für Klavier' (ED 8883) was published in 1999. It contains a large variety of short piano pieces the fundamental notes of which are obtained by permutation from a twelve-note series from Schoenberg's Suite for Piano Op. 25. An updated edition was published in 2015. Another 16 compositions created between 2014 and 2019 can now be added to these pieces with this supplement (ED 8883-01). In 1999, the 'Tagebuch für Klavier' was awarded the ''Deutscher Musikeditionspreis''.