http://science.kennesaw.edu/~plaval/mathnotes/FourierSeries.pdf
http://www.cse.salford.ac.uk/profiles/gsmcdonald/H-Tutorials/Fourier-series-tutorial.pdf
http://people.ee.duke.edu/maxim/teaching/fall08/lec8.pdf
http://people.math.carleton.ca/~amingare/calculus/fourier-series.pdf
http://www.stewartcalculus.com/data/CALCULUS%20Early%20Transcendentals/upfiles/FourierSeries5ET.pdf
http://math.bard.edu/belk/math461/FourierSeries.pdf
