Sources for the following files:
ucum-essence.xml: http://aurora.regenstrief.org/~ucum/ucum-essence.xml
UcumFunctionalTests.xml: http://www.unitsofmeasure.org/wiki/FunctionalTests (better: ask Grahame Grieve 'grahame@healthintersections.com.au' / skype: grahamegrieve)