Farooq, U., Kannampallil, T. G., Song, Y., Ganoe, C. H., Carroll, J. M. & Giles, L. (2007). Evaluating tagging behavior in social bookmarking systems: metrics and design heuristics. GROUP '07: Proceedings of the 2007 international ACM conference on Conference on supporting group work (p./pp. 351--360), New York, NY, USA: ACM. ISBN: 978-1-59593-845-9

Farooq, U., Song, Y., Carroll, J. M. & Giles, C. L. (2007). Social Bookmarking for Scholarly Digital Libraries. IEEE Internet Computing, 11, 29--35. doi: http://dx.doi.org/10.1109/MIC.2007.135