@Manual{Rsystem,
    title = {R: A Language and Environment for Statistical Computing},
    author = {{R Development Core Team}},
    organization = {R Foundation for Statistical Computing},
    address = {Vienna, Austria},
    year = {2013},
    note = {Available from \url{http://www.R-project.org}}
  }

@MISC{greport,
  author = {Harrell, Frank E.},
  year = 2014,
  title = {\texttt{greport}: {R} functions for graphical reporting of clinical trials.},
  howpublished = {Available from \url{hbiostat.org/R/greport}}
}

@MISC{Hmisc,
  author = {Harrell, Frank E.},
  year = 2014,
  title = {{\tt Hmisc}: {A} package of miscellaneous \textsc{R} functions},
  howpublished = {Available from 
                 \url{hbiostat.org/R/Hmisc}}
}

@MISC{rrms,
  author = {Harrell, Frank E.},
  year = 2013,
  title = {\texttt{rms}: {S} functions for biostatistical/epidemiologic
          modeling, testing, estimation, validation, graphics, prediction, and
          typesetting by storing enhanced model design attributes in the fit},
  note = {Implements methods in \emph{Regression Modeling Strategies}, New York:Springer, 2001},
  howpublished = {Available from \url{hbiostat.org/R/rms}}
}

@Book{knitrbook,
	author = 	 {Yihui Xie},
	title = 			 {Dynamic Documents with R and \texttt{knitr}},
	publisher = 	 {Chapman and Hall},
	year = 				 2013,
  note = {ISBN 978-1482203530}}
