@ARTICLE{Vilim2005Constraints,
  author = {Petr Vil{\'i}m and Roman Bart{\'a}k and Ond\v{r}ej {\v{C}}epek},
  title = {Extension of $\uppercase{o}(n \log n)$ Filtering Algorithms for the
	Unary Resource Constraint to Optional Activities},
  journal = {Contraints},
  year = {2005},
  volume = {10},
  pages = {403--425},
  number = {4},
  month = {October},
  issn = {1383-7133},
  publisher = {Kluwer Academic Publishers},
  url = {http://vilim.eu/petr/constraints2005.pdf}
}