@misc{Wuertz2012,
author = {Wuertz, D. and Chalabi, Y. and Maechler, M.  Version . },
title= {timeDate: Rmetrics– Chronological and calendar objects},
year = {2012},
URL = {http://cran.r-project.org/web/packages/timeDate/index.html},
note = {(Accessed January 16, 2013)},
edition = {2160.97},
}