Cita APA (7th ed.)
ebrary, Inc. (1991). The U.S. National Plant Germplasm System. National Academy Press.
Cita Chicago (17th ed.)
ebrary, Inc. The U.S. National Plant Germplasm System. Washington, D.C.: National Academy Press, 1991.
Cita MLA (9th ed.)
ebrary, Inc. The U.S. National Plant Germplasm System. National Academy Press, 1991.
Atenció: Aquestes cites poden no estar 100% correctes.