APA (7th ed.) Citation

Schelle, H., Ottmann, R., & Pfeiffer, A. (2006). Project manager (1. English language ed.). GPM.

Chicago Style (17th ed.) Citation

Schelle, Heinz, Roland Ottmann, and Astrid Pfeiffer. Project Manager. 1. English language ed. Nuremberg: GPM, 2006.

MLA (9th ed.) Citation

Schelle, Heinz, et al. Project Manager. 1. English language ed. GPM, 2006.