Black, K. (2004). Business Statistics (4th.). John Wiley & Sons.
Cita Chicago (17th ed.)Black, Ken. Business Statistics. 4th. John Wiley & Sons, 2004.
Cita MLA (9th ed.)Black, Ken. Business Statistics. 4th. John Wiley & Sons, 2004.
Atenció: Aquestes cites poden no estar 100% correctes.