APA   Click to copy
Hsieh, G., Hudson, S. E., & Kraut, R. E. (2011). Donate for credibility: how contribution incentives can improve credibility. Human Factors in Computing Systems, 3435–3438.

Chicago/Turabian   Click to copy
Hsieh, Gary, Scott E. Hudson, and Robert E. Kraut. “Donate for Credibility: How Contribution Incentives Can Improve Credibility.” Human Factors in Computing Systems (April 6, 2011): 3435–3438.

MLA   Click to copy
Hsieh, Gary, et al. “Donate for Credibility: How Contribution Incentives Can Improve Credibility.” Human Factors in Computing Systems, Apr. 2011, pp. 3435–38.

@article{gary2011a,
  title = {Donate for credibility: how contribution incentives can improve credibility},
  year = {2011},
  month = apr,
  day = {6},
  journal = {Human Factors in Computing Systems},
  pages = {3435-3438},
  author = {Hsieh, Gary and Hudson, Scott E. and Kraut, Robert E.},
  booktitle = {chi},
  month_numeric = {4}
}