@book{76611,
	author = {Harrell, Frank E.},
	title = {Regression modeling strategies  with applications to linear models, logistic regression, and survival analysis},
	publisher = {Springer},
	year = {2001},
	series = {Springer Series in Statistics},
	address = {Nueva York (Estados Unidos)},
	url = { http://www.loc.gov/catdir/enhancements/fy0816/2001020045-t.html}
}