Jäschke, R., Marinho, L., Hotho, A., Schmidt-Thieme, L. & Stumme, G.
(2008).
Tag Recommendations in Social Bookmarking Systems. AI Communications,
21, 231-247.
doi: 10.3233/AIC-2008-0438
Golder, S. & Huberman, B. A.
(2005).
The Structure of Collaborative Tagging Systems