Dyfyniad APA
ebrary, Inc. (1999). How abundant?: Assessing the estimates of natural gas supply. Environmental Law Institute.
Dyfyniad Arddull Chicago
ebrary, Inc. How Abundant?: Assessing the Estimates of Natural Gas Supply. Washington, D.C.: Environmental Law Institute, 1999.
Dyfyniad MLA
ebrary, Inc. How Abundant?: Assessing the Estimates of Natural Gas Supply. Environmental Law Institute, 1999.
Rhybudd: Mae'n bosib nad yw'r dyfyniadau hyn bob amser yn 100% cywir.