Blank, S. G. (2013). The four steps to the epiphany: Successful strategies for products that win (4th ed.). [California]: S. G. Blank.
Παραπομπή Chicago StyleBlank, Steven G. The Four Steps to the Epiphany: Successful Strategies for Products That Win. 4th ed. [California]: S. G. Blank, 2013.
Παραπομπή MLABlank, Steven G. The Four Steps to the Epiphany: Successful Strategies for Products That Win. 4th ed. [California]: S. G. Blank, 2013.
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