1. Bates, D., Maechler, M.: Matrix: A Matrix package for R. See the nearPD function in this R package for methods of forcing positive definiteness (2008),
http://cran.r-project.org/web/packages/Matrix/index.html
2. Breiman, Friedman, Olshen, Stone: Classification and Regression Trees. Wadsworth (1984)
3. Cootes, T.F., Cooper, D.H., Taylor, C.J., Graham, J.: A Trainable Method of Parametric Shape Description. BMVC 2, 54–61 (1991)
4. Cootes, T.F., Taylor, C.J., Cooper, D.H., Graham, J.: Active Shape Models — their Training and Application. CVIU 61, 38–59 (1995)
5. Lecture Notes in Computer Science;T.F. Cootes,1998