Ellis, C. D. (2020). What it takes: Seven secrets of success from the world's greatest professional firms (Unabridged.). Gildan Audio.
Chicago-Zitierstil (17. Ausg.)Ellis, Charles D. What It Takes: Seven Secrets of Success from the World's Greatest Professional Firms. Unabridged. New York: Gildan Audio, 2020.
MLA-Zitierstil (9. Ausg.)Ellis, Charles D. What It Takes: Seven Secrets of Success from the World's Greatest Professional Firms. Unabridged. Gildan Audio, 2020.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.