@inproceedings{van2006opf,
  title = "Opf: a distributed context-sensing framework for ubiquitous computing environments",
  author = "Van Kleek and Max and Kunze, Kai and Partridge, Kurt and others",
  year = "2006",
  booktitle = "International Symposium on Ubiquitious Computing Systems",
  organization = "Springer, Berlin, Heidelberg",
  pages = "82--97",
}