References

http://lucidcafe.com/library/95dec/newton.html

www.bbc.co.uk/history/historic_figures/newton_isaac.shtml

www.newton.cam.ac.uk/newtlife.html

http://encarta.msn.com/encnet/features/home.asp

http://csep10.phys.utk.edu/astr161/lect/history/newtongrav.html

www.top-biography.com/0016-Isaac%20Newton/achievement1.htm

www.blupete.com/Literature/Biographies/Science/Newton.htm

www.bartleby.com/65/ne/Newton-S.html

"Newton, Sir Isaac." Encyclopaedia Britannica. 2003. Encyclopaedia Britannica Online.  14 Apr, 2003.  http://search.eb.com/eb/article?eu=115657.

Physics: for Scientists and Engineers. Thomson Learning Inc., 2000.