deletions | additions       diff --git a/Introduction.tex b/Introduction.tex  index 15b5df8..0d20097 100644  --- a/Introduction.tex  +++ b/Introduction.tex 
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\url{http://faculty.csusm.edu/oskoorouchi/silp5.pdf}  \url{ftp://ftp.cs.wisc.edu/pub/dmi/tech-reports/00-01.pdf}  \url{http://www.math.washington.edu/~morrow/mcm/uw25.pdf} \url{http://web.archive.org/web/20140715223826/http://bendwavy.org/sphere.htm]