Inproceedings (grahl2007clustering)
Grahl, M.; Hotho, A. & Stumme, G.
Conceptual Clustering of Social Bookmarking Sites
Know-Center, 2007, 356-364

Inproceedings (jaschke07recommender)
Jäschke, R.; Marinho, L. B.; Hotho, A.; Schmidt-Thieme, L. & Stumme, G.
Kok, J. N.; Koronacki, J.; de Mántaras, R. L.; Matwin, S.; Mladenic, D. & Skowron, A. (ed.)
Tag Recommendations in Folksonomies
Springer, 2007, 4702, 506-514