Babbage, K. J. (2010). The extreme principle: What matters most, what works best. Rowman & Littlefield Education.
芝加哥风格引文Babbage, Keen J. The Extreme Principle: What Matters Most, What Works Best. Lanham: Rowman & Littlefield Education, 2010.
MLA引文Babbage, Keen J. The Extreme Principle: What Matters Most, What Works Best. Rowman & Littlefield Education, 2010.
警告：这些引文格式不一定是100％准确.