@article{acmcs-time,
  author	= {Hardman, Lynda and van Ossenbruggen, Jacco and Rutledge, Lloyd and Bulterman, Dick C. A.},
  URL		= {http://www.cwi.nl/$~$media/publications/acmcs.submission.html},
  urlpage	= {http://www.cwi.nl/$~$media/publications/acmcs.submission.html},
  title		= {Hypermedia: The Link with Time},
  year		= {1999},
  journal	= {ACM Computing Surveys},
  month		= dec
}