avail @ http://www.ericsworld.com/Mark/ papers @ http://www.informatik.fernuni-hagen.de/import/pi4/erwig/papers/abstracts.html dads @ http://hissa.nist.gov/dads/terms.html pl xref @ http://www.geocities.com/SiliconValley/Way/9731/xref.html brain @ http://brain.sourceforge.net/