25 Technical studies for string bass, Op. 14, Book 4, by Theodor Findeisen (1881 - 1936). Edited by Fred Zimmermann; published by International Music Co., 1957. This volume (Book 4) contains studies 21-25. Findeisen was a pupil of Simandl, and though many of his compositions have become difficult to acquire, this collection of studies is well-known as challenging etudes for the developing bassist.