http://en.wikipedia.org/wiki/Modulation

http://www.tscm.com/modulate.pdf

http://en.wikibooks.org/wiki/Communication_Systems/What_is_Modulation%3F

http://en.wikipedia.org/wiki/Amplitude_modulation

http://en.wikibooks.org/wiki/Communication_Systems/Amplitude_Modulation

http://www.soundonsound.com/sos/mar00/articles/synthsecrets.htm

http://demonstrations.wolfram.com/AmplitudeModulation/

http://robotics.eecs.berkeley.edu/~sastry/ee20/modulation/node3.html

http://www.st-andrews.ac.uk/~www_pa/Scots_Guide/RadCom/part9/page1.html

https://ccrma.stanford.edu/~jos/st/Sinusoidal_Amplitude_Modulation_AM.html

http://www.google.com/url?sa=t&rct=j&q=amplitude+modulation+example&source=web&cd=11&cad=rja&ved=0CG0QFjAK&url=http%3A%2F%2Fwww.ece.uvic.ca%2F~weili%2FAM1.ppt&ei=ePHnUPOgN8mHtQap1oEg&usg=AFQjCNFsWZY56_5M2UhU8iBa7iBAqhthsg&bvm=bv.1355534169,d.Yms

http://itee.uq.edu.au/~coms3100/Lecture%20Notes/lec09.pdf

http://local.eleceng.uct.ac.za/courses/EEE3086F/labs/EEE3086F%20Introduction%20to%20Simulink.pdf

http://my.safaribooksonline.com/book/-/9781856177009/modulation/amplitude_modulation#X2ludGVybmFsX0J2ZGVwRmxhc2hSZWFkZXI/eG1saWQ9OTc4MTg1NjE3NzAwOS8xNjE=