@TechReport{BRICS-RS-04-7,
  author =	 "M. K{\v{r}}et\'{\i}nsk\'{y} and V. {\v{R}}eh\'{a}k and J. Strej\v{c}ek",
  title =	 "{On the Expressive Power of Extended Process Rewrite Systems}",
  institution =	 "Basic Research in Computer Science, Aarhus, Denmark",
  year =	 "2004",
  number =	 "RS-04-07, 12pp",
  ISSN =	 "0909-0878"
}