Fabian Abel Matteo Baldoni Cristina Baroglio Nicola Henze Daniel Krause Viviana Patti Context-based ranking in folksonomies. 209-218 2009 Hypertext http://doi.acm.org/10.1145/1557914.1557951 conf/ht/2009 db/conf/ht/ht2009.html#AbelBBHKP09