This collection of short studies is based on Carl Czerny’s 125 Exercises in Passage Playing, Op. 261, Nos. 1-25. Some of the studies in this set are mere reharmonisations of Czerny’s original exercise while others are original compositions which address the same (or similar) technical points as Czerny’s original. To get the most out of this set, I recommend studying the original Czerny versions before you study these.
(I plan to eventually complete the set of all 125 studies from Czerny's Op. 261 but for now only nos.1 to 25 are available.)