Cita APA (7th ed.)
ebrary, Inc. (2000). The impact of selling the federal helium reserve. National Academy Press.
Cita Chicago (17th ed.)
ebrary, Inc. The Impact of Selling the Federal Helium Reserve. Washingon, D.C.: National Academy Press, 2000.
Cita MLA (9th ed.)
ebrary, Inc. The Impact of Selling the Federal Helium Reserve. National Academy Press, 2000.
Atenció: Aquestes cites poden no estar 100% correctes.