Kreitner, R. &. O. (1990). Business. Houghton.
Dyfyniad Arddull ChicagoKreitner, Robert & Others. Business. Houghton, 1990.
Dyfyniad MLAKreitner, Robert & Others. Business. Houghton, 1990.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.