Cita APA (7th ed.)

Babbage, K. J. (2010). The extreme principle: What matters most, what works best. Rowman & Littlefield Education.

Cita Chicago (17th ed.)

Babbage, Keen J. The Extreme Principle: What Matters Most, What Works Best. Lanham: Rowman & Littlefield Education, 2010.

Cita MLA (9th ed.)

Babbage, Keen J. The Extreme Principle: What Matters Most, What Works Best. Rowman & Littlefield Education, 2010.