References:

The Plastic Ball:

http://mipp-docdb.fnal.gov/cgi-bin/RetrieveFile?docid=172&version=1&filename=loehner.ppthttp://wa98.web.cern.ch/WA98/ball.shtmlhttp://wa98.web.cern.ch/WA98/PICTURES/Detectors/pbsdd.html

The properties and applications of the CaF2:

http://www.azom.com/details.asp?ArticleID=2960