http://books.google.com/books/about/Sampling_Theory_in_Fourier_and_Signal_An.html?id=vUwFTCXK_QcC

http://books.google.com/books?id=Ti9kwQpmMSIC&source=gbs_similarbooks

http://www.dspguide.com/CH3.PDF

http://my.safaribooksonline.com/book/electrical-engineering/communications-engineering/0131089897/periodic-sampling/ch02lev1sec2