"Elbe." The Columbia Encyclopedia, Sixth Edition. 2008. Encyclopedia.com. 7 Dec. 2009 <http://www.encyclopedia.com>.
"Elbe." The Columbia Encyclopedia, Sixth Edition. 2008. Encyclopedia.com. (December 7, 2009). http://www.encyclopedia.com/doc/1E1-Elbe.html
"Elbe." The Columbia Encyclopedia, Sixth Edition. 2008. Retrieved December 07, 2009 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-Elbe.html