http://www.amasci.com/esloud/eslhwto.html
http://www.izzy-wizzy.com/audio/spkr.html
http://www-mddsp.enel.ucalgary.ca/People/madanayake/ghana_files/audio.htm
http://www.geocities.com/neurot_sloth/ESL.html
http://www.ele.tut.fi/~artoko/audio/speakers/esl.html
http://www.diyaudio.com/forums/forumdisplay.php?s=&forumid=54
http://members.tripod.com/~mdarling/
http://www.simplystax.co.uk/heritage_products.html
http://www.stevehoffman.tv/forums/showthread.php?t=52589
http://www.integracoustics.com/MUG/MUG/tweaks/quad/hey_you/57.html
http://www.go.to/mtaudio
http://www.quadesl.org/Fixit/fixit.html
http://www.quadesl.com/
http://www.janszenloudspeaker.com/index.htm
http://www.tnt-audio.com/casse/vanmedevoort150_e.html
http://sound.westhost.com/project105.htm
http://welcome.to/eslsystems
http://www.artsandmedia.com/audio.html
Regards Moray James.