Zeileis A, Grothendieck G (2005). “zoo: S3 Infrastructure for Regular and Irregular Time Series.” Journal of Statistical Software, 14(6), 1–27. doi:10.18637/jss.v014.i06.
@Article{,
title = {zoo: S3 Infrastructure for Regular and Irregular Time Series},
author = {Achim Zeileis and Gabor Grothendieck},
journal = {Journal of Statistical Software},
year = {2005},
volume = {14},
number = {6},
pages = {1--27},
doi = {10.18637/jss.v014.i06},
}