Notes on software testing:
http://agilesoftwaredevelopment.com/blog/janusz-gorycki/your-unit-tests-are-useless
http://ivory.idyll.org/blog/necessity-vs-sufficiency.html
http://binstock.blogspot.no/2007/11/fallacy-of-100-code-coverage.html
http://nedbatchelder.com/code/coverage/