APA   Click to copy
Ferreira, D., Dey, A. K., & Kostakos, V. (2011). Understanding human-smartphone concerns: a study of battery life. International Conference on Pervasive Computing, 19–33.

Chicago/Turabian   Click to copy
Ferreira, Denzil, Anind K. Dey, and Vassilis Kostakos. “Understanding Human-Smartphone Concerns: a Study of Battery Life.” International Conference on Pervasive Computing (May 11, 2011): 19–33.

MLA   Click to copy
Ferreira, Denzil, et al. “Understanding Human-Smartphone Concerns: a Study of Battery Life.” International Conference on Pervasive Computing, May 2011, pp. 19–33.

@article{denzil2011a,
  title = {Understanding human-smartphone concerns: a study of battery life},
  year = {2011},
  month = may,
  day = {11},
  journal = {International Conference on Pervasive Computing},
  pages = {19-33},
  author = {Ferreira, Denzil and Dey, Anind K. and Kostakos, Vassilis},
  booktitle = {pervasive},
  month_numeric = {5}
}