John Krogstie Arthur Jahr Dag I. K. Sjøberg A longitudinal study of development and maintenance in Norway: Report from the 2003 investigation. 993-1005 2006 48 Information & Software Technology 11 http://dx.doi.org/10.1016/j.infsof.2005.12.008 db/journals/infsof/infsof48.html#KrogstieJS06