Dyfyniad APA
ebrary, Inc. (1986). Soil conservation: Assessing the national resources inventory. National Academy Press.
Dyfyniad Arddull Chicago
ebrary, Inc. Soil Conservation: Assessing the National Resources Inventory. Washington, D.C.: National Academy Press, 1986.
Dyfyniad MLA
ebrary, Inc. Soil Conservation: Assessing the National Resources Inventory. National Academy Press, 1986.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.