http://www.earthcurrents.com/london-live/systems/LD_system.htm
http://www.earthcurrents.com/london-live/systems/LD_system.htm
http://www.earthcurrents.com/london-live/systems/LD_system.htm
http://www.buenzow.de/english/mystat.htm
http://www.ossaudio.com/cadencemain.htm
http://www-personal.engin.umich.edu/~jglettle/section/rapture/esltheory.html
http://ccrma.stanford.edu/~byoink/220c/est.htm
http://www.dayton-wright.com/index.shtml
http://www.dayton-wright.com/XG-8-Mk3.html
http://www.onethingaudio.com/
http://pkant.htmlplanet.com/elstatr.htm
http://www.sowter.co.uk/2esl.htm
http://www.audio4.nl/enproducts.htm
http://werple.net.au/~kiewavly/esl.html
http://www.justrealmusic.com/
http://www.eraudio.com.au/
http://www.sacdmods.com/ESL/
http://www.quadesl.org.uk/