Black, K. (2004). Business Statistics (4th.). John Wiley & Sons.
Lua i Stíl Chicago (17ú heag.)Black, Ken. Business Statistics. 4th. John Wiley & Sons, 2004.
Lua MLA (9ú heag.)Black, Ken. Business Statistics. 4th. John Wiley & Sons, 2004.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.