@inproceedings{DBLP:conf/lisa/Sparks06,
  author    = {Robert Sparks},
  title     = {VoIP},
  booktitle = {LISA},
  year      = {2006},
  crossref  = {DBLP:conf/lisa/2006},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}

@proceedings{DBLP:conf/lisa/2006,
  title     = {Proceedings of the 20th Conference on Systems Administration
               (LISA 2006), Washington, DC, USA, December 3-8, 2006},
  booktitle = {LISA},
  publisher = {USENIX},
  year      = {2006},
  bibsource = {DBLP, http://dblp.uni-trier.de}
}