Jefferson Lab, Science Education. “ It’s Elemental (Cobalt).” Steve Gagnon. 24 March 2003. <http://education.jlab.org/itselemental/ele027.html>
 

The Chemistry Place. “Cobalt.” 1997. Mark Winter. 24 March 2003. <http://www.chemplace.com/periodic/Co.html#describe>
 

ISPT Periodic Table for the Web. “Cobalt.” 24 Feb 2003. Qivx Inc. 24 March 2003. <http://www.qivx.com/ispt/elements/ispt_027.htm>
 

Chemistry: WebElements Periodic Table: Professional Edition. “Cobalt.” 2003. Mark Winter. 25 March 2003. <http://www.webelements.com/webelements/elements/text/Co/key.html>
 

Bentor, Yinon. Chemical Element.com - Cobalt. 29 March 2003 <http://www.chemicalelements.com/elements/co.html>
 

CST Information Services Team. Period Table- Cobalt. 19 Dec 1997. 26 March 2003. <http://pearl1.lanl.gov/periodic/elements/27.html>

Atlantic Metals and Alloys, Inc. "Cobalt." 29 March 2003. <http://www.atlanticmetals.com/>

Young, Robyn V. (2000). World of Chemistry. Farmington Hills, Michigan: Gale Group.

Parker, Sybil P. (1993) McGraw-Hill Encyclopedia of Chemistry: Second Edition. New York: McGraw- Hill, INC.

Stwertka, Albert. (1996). A Guide to the Elements. New York, New York: Oxford University Press INC.

Emsley, John. (2001). Nature's Building Blocks: An A-Z Guide to the Elements. New York, New York: Oxford University Press INC.