My sources are:

• Heiserman, David. Exploring Chemical Element and their Compound.

• MSAccess, FrontPage97, and SAS. Mineralogy Dabatase. Since January 8, 1999.< http://web.wt.net/~daba/Mineral/chemical.html >

• The Bromine Science and Environmental Forum (BSEF). Hosted & Developed by YMP. Where is Bromine used? <http://www.bsef.com/WhereBromineIsUsed.htm>

• University of Illinois at Urbana-Champaign. Addition of bromine to hydrocarbons. <http://www.chem.uiuc.edu/demos/cyclo.html>

• Winter, Mark "Web elements" University of Sheffield, England. Abundance of elements (Earth's crust)

  <http://www.shef.ac.uk/~chem/web-elements/pics-c-nt/abundance-crust-c.html>