APA način citiranja (7. izdanje)
Babbage, K. J. (2010). The extreme principle: What matters most, what works best. Rowman & Littlefield Education.
Čikaški stil citiranja (17. izdanje)
Babbage, Keen J. The Extreme Principle: What Matters Most, What Works Best. Lanham: Rowman & Littlefield Education, 2010.
MLA način citiranja (9. izdanje)
Babbage, Keen J. The Extreme Principle: What Matters Most, What Works Best. Rowman & Littlefield Education, 2010.
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