http://www.analog.com/library/analogdialogue/archives/43-09/edch%204%20rf%20if.pdf
http://www.navymars.org/national/training/nmo_courses/nmoc/module17/14189_ch2.pdf
http://www.navymars.org/national/training/
http://www.navymars.org/national/training/nmo_courses/nmoc/NMOC.htm
http://www.navymars.org/national/training/nmo_courses/nmoc/