Edition Dux Smart Practicing – Ein Improvisationskurs for alle Instrumente im Treble Clef: Textbook on improvisation, by Christian Tschuggnall and Markus Ehrlich, ISBN 9783868493245, ISMN 9790500174974, D 2128, A4, spiral binding, 114 pages, in German language, incl.iOS app, the full version of the ""Smart Practicing"" app for iPhone and iPad is included with the purchase of this book