6Efroymson, M. A.. Multiple Regression Analysis in Proceedings' Multiple regression analysis' (A. Raston and H.S. Vilf ed.)[M]. John Wiley 1960:191-203.
7SAS Institute, SAS/STAT 9.1 User's Guide[M]. SAS Publishing, 2004:6.
8Draper, N. R., Smith, H.. Applied Regression Analysis[M]. John Wiley & Sons, 1998.