Koch, R. (1998). The 80/20 principle: The secret of achieving more with less. London Sonoma, Calif., USA: Nicholas Brealey.
Παραπομπή Chicago StyleKoch, Richard. The 80/20 Principle: The Secret of Achieving More With Less. London Sonoma, Calif., USA: Nicholas Brealey, 1998.
Παραπομπή MLAKoch, Richard. The 80/20 Principle: The Secret of Achieving More With Less. London Sonoma, Calif., USA: Nicholas Brealey, 1998.
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