Dyfyniad APA

Barbier, E. B., Acreman, M., & Knowler, D. (1997). Economic valuation of wetlands: A guide for policy makers and planners. Ramsar Convention Bureau.

Dyfyniad Arddull Chicago

Barbier, Edward B., Mike Acreman, and Duncan Knowler. Economic Valuation of Wetlands: A Guide for Policy Makers and Planners. Gland, Switzerland: Ramsar Convention Bureau, 1997.

Dyfyniad MLA

Barbier, Edward B., et al. Economic Valuation of Wetlands: A Guide for Policy Makers and Planners. Ramsar Convention Bureau, 1997.

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