Ball, R. (1991). Quantitative approaches to management. Butterworth Heinemann.
Lua i Stíl Chicago (17ú heag.)Ball, Robert. Quantitative Approaches to Management. Oxford: Butterworth Heinemann, 1991.
Lua MLA (9ú heag.)Ball, Robert. Quantitative Approaches to Management. Butterworth Heinemann, 1991.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.