References

1. A. Heck, F. Murtagh, D. Ponz, ``The increasing importance of statistical methods in astronomy'', The Messenger, No. 41, 22--25, Sept. 1985.
2. An inventory of astronomical and general references, under headings related to major multivariate methods, is available. It is described in F. Murtagh and A. Heck, ``An annotated bibliographical catalogue of multivariate statistical methods and of their astronomical applications'', Astronomy and Astrophysics Supplement Series 68 113--115, 1987.
3. A text--book fully describing the algorithms implemented here and with many examples is: F. Murtagh and A. Heck, Multivariate Data Analysis, Kluwer (Astrophysics and Space Science Library), Dordrecht, 1987.