A correctly formatted reference will tell you exactly where to find the full article:
DING, Y., JACOB, E. K., ZHIXIONG, Z., FOO, S., ERJIA, Y., GEORGE, N. L. and LIJIANG, G. (2009) Perspectives on social tagging, Journal of the American Society for Information Science and Technology, 60 (12), 2388-2401.
This article was written by Y Ding & colleagues, and the article's title is "Perspectives on social tagging". It was published in 2009 in the journal called "Journal of the American Society for Information Science and Technology". It was published in volume 60, issue 12, and the article ran from page 2388 to 2401.