(2001). Cost-benefit analysis. Prentice Hall.
Dyfyniad Arddull ChicagoCost-benefit Analysis. Prentice Hall, 2001.
Dyfyniad MLACost-benefit Analysis. Prentice Hall, 2001.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.
(2001). Cost-benefit analysis. Prentice Hall.
Dyfyniad Arddull ChicagoCost-benefit Analysis. Prentice Hall, 2001.
Dyfyniad MLACost-benefit Analysis. Prentice Hall, 2001.