Links
http://www.chemicalelements.com/elements/ce.html
"Chemical Elements.com - Cerium (Ce)." Chemical Elements.com - Cerium (Ce). N.p., n.d. Web. 28 Nov. 2012.
http://www.webelements.com/cerium/
http://www.lenntech.com/periodic/elements/ce.htm
http://www.chemicool.com/elements/cerium.html
"Chemical Elements.com - Cerium (Ce)." Chemical Elements.com - Cerium (Ce). N.p., n.d. Web. 28 Nov. 2012.
http://www.webelements.com/cerium/
http://www.lenntech.com/periodic/elements/ce.htm
http://www.chemicool.com/elements/cerium.html