Tim Menzies Oussama El-Rawas Barry W. Boehm Raymond J. Madachy Jairus Hihn Daniel Baker Karen T. Lum Accurate Estimates without Calibration?. 210-221 2008 ICSP http://dx.doi.org/10.1007/978-3-540-79588-9_19 conf/ispw/2008 db/conf/ispw/icsp2008.html#MenziesEBMHBL08