Layard, P. R. G. (1972). Cost-benefit analysis: Selected readings. Penguin Education.
Dyfyniad Arddull ChicagoLayard, P. R. G. Cost-benefit Analysis: Selected Readings. Harmondsworth, Eng. ; Baltimore: Penguin Education, 1972.
Dyfyniad MLALayard, P. R. G. Cost-benefit Analysis: Selected Readings. Penguin Education, 1972.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.