Cita APA (7th ed.)

Helder, C. (2014). The Ultimate book of Influence. Wiley India.

Cita Chicago (17th ed.)

Helder, Chris. The Ultimate Book of Influence. New Delhi: Wiley India, 2014.

Cita MLA (9th ed.)

Helder, Chris. The Ultimate Book of Influence. Wiley India, 2014.