Jason Chong Lee D. Scott McCrickard Towards Extreme(ly) Usable Software: Exploring Tensions Between Usability and Agile Software Development. 59-71 2007 conf/agiledc/2007 AGILE http://doi.ieeecomputersociety.org/10.1109/AGILE.2007.63 db/conf/agiledc/agile2007.html#LeeM07