John Domingue Liliana Cabral Stefania Galizia Vlad Tanasescu Alessio Gugliotta Barry Norton Carlos Pedrinaci 109-132 2008 6 J. Web Sem. 2 http://dx.doi.org/10.1016/j.websem.2008.01.001 db/journals/ws/ws6.html#DomingueCGTGNP08