Wolfgang May Modeling and Querying Structure and Contents of the Web. 721-725 1999 conf/dexaw/1999 DEXA Workshop https://doi.org/10.1109/DEXA.1999.795273 https://doi.ieeecomputersociety.org/10.1109/DEXA.1999.795273 db/conf/dexaw/dexaw99.html#May99