Richards, L. E. (1983). Business statistics: Why and when (2nd ed.). McGraw - Hill.
Dyfyniad Arddull ChicagoRichards, Larry E. Business Statistics: Why and When. 2nd ed. New York: McGraw - Hill, 1983.
Dyfyniad MLARichards, Larry E. Business Statistics: Why and When. 2nd ed. McGraw - Hill, 1983.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.