APA   Click to copy
Dey, A. K., Hightower, J., de Lara, E., & Davies, N. (2009). Location-Based Services. IEEE Pervasive Computing, 9(1), 11–12.

Chicago/Turabian   Click to copy
Dey, Anind K., Jeffrey Hightower, Eyal de Lara, and Nigel Davies. “Location-Based Services.” IEEE Pervasive Computing 9, no. 1 (November 31, 2009): 11–12.

MLA   Click to copy
Dey, Anind K., et al. “Location-Based Services.” IEEE Pervasive Computing, vol. 9, no. 1, Nov. 2009, pp. 11–12.

@article{anind2009a,
  title = {Location-Based Services},
  year = {2009},
  month = nov,
  day = {31},
  issue = {1},
  journal = {IEEE Pervasive Computing},
  pages = {11-12},
  volume = {9},
  author = {Dey, Anind K. and Hightower, Jeffrey and de Lara, Eyal and Davies, Nigel},
  month_numeric = {11}
}