http://site.iugaza.edu.ps/aliafana/files/2010/04/02_analog_filters.pdf
http://en.wikibooks.org/wiki/Signals_and_Systems/Filter_Implementations
http://faculty.cua.edu/regalia/ee362/inv-cheb-design-example.pdf
http://www.matheonics.com/Tutorials/InverseChebyshev.html
http://www.etc.tuiasi.ro/cin/Downloads/Filters/Filters.htm
http://www.filter-solutions.com/chevy2.html
http://eceweb1.rutgers.edu/~orfanidi/ece521/notes.pdf
http://www.matheonics.com/Tutorials/InverseChebyshev.html