Gaya APA

Drucker, P, F. et al (2015). Peter Drucker's Five Most Important Questions: Enduring Wisdom for Today's Leaders . Amerika Serikat: Wiley.

Gaya MLA

Drucker, Peter, F.. et al. "Peter Drucker's Five Most Important Questions: Enduring Wisdom for Today's Leaders". Amerika Serikat: Wiley, 2015. Text.