Dyfyniad APA

Costa, D. L. (1999). American living standards: Evidence from recreational expenditures. National Bureau of Economic Research.

Dyfyniad Arddull Chicago

Costa, Dora L. American Living Standards: Evidence from Recreational Expenditures. Cambridge: National Bureau of Economic Research, 1999.

Dyfyniad MLA

Costa, Dora L. American Living Standards: Evidence from Recreational Expenditures. National Bureau of Economic Research, 1999.

Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.