@book {IOPORT.20005752,
    editor       = {Cattuto, Ciro and Ruffo, Giancarlo and Menczer, Filippo},
    title        = {HYPERTEXT 2009, Proceedings of the 20th ACM conference on hypertext and hypermedia, Torino, Italy, June 29 - July 1, 2009},
    year         = {2009},
    isbn         = {978-1-60558-486-7},
    publisher    = {ACM},
    identifier   = {20005752},
}