http://www.google.com/url?sa=t&rct=j&q=amplitude%20modulation&source=web&cd=7&cad=rja&ved=0CEwQFjAG&url=http%3A%2F%2Fwww.home.agilent.com%2Fowc_discussions%2Fservlet%2FJiveServlet%2Fdownload%2F71-33948-103934-5301%2FAM%2520fundamentals%2520pages%2520103-104.pdf&ei=9-7nUN73Kcjesgawx4CwBw&usg=AFQjCNHwPKoxr6ekNIVGdqt8uvFYjrLn1A

http://www.berk.tc/combas/chapter4.pdf

http://www.ece.umd.edu/~tretter/commlab/c6713slides/ch5.pdf

http://ocw.mit.edu/resources/res-6-007-signals-and-systems-spring-2011/lecture-notes/MITRES_6_007S11_lec13.pdf