Ismael Sanz Marco Mesiti Giovanna Guerrini Rafael Berlanga Llavori An Entropy-Based Characterization of the Heterogeneity of XML Collections. 238-242 2008 DEXA Workshops http://doi.ieeecomputersociety.org/10.1109/DEXA.2008.55 conf/dexaw/2008 db/conf/dexaw/dexaw2008.html#SanzMGL08