Dyfyniad APA
ebrary, Inc, Nordhaus, W. D., & Kokkelenberg, E. C. (1999). Nature's numbers: Expanding the national economic accounts to include the environment. National Academy Press.
Dyfyniad Arddull Chicago
ebrary, Inc, William D. Nordhaus, and Edward Charles Kokkelenberg. Nature's Numbers: Expanding the National Economic Accounts to Include the Environment. Washington, D.C.: National Academy Press, 1999.
Dyfyniad MLA
ebrary, Inc, et al. Nature's Numbers: Expanding the National Economic Accounts to Include the Environment. National Academy Press, 1999.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.