@misc{9839,
  author = {Yan Zhang},
  title = {Spectrum Handoff in Cognitive Radio Networks: Opportunistic and Negotiated Situations},
  year = {2009},
  journal = {the IEEE International Conference on Communications (ICC), ICC 2009},
  publisher = {IEEE},
  isbn = {978-1-4244-3435-0},
  editor = {IEEE},
}