Thomas Herrmann Marcel Hoffmann Isa Jahnke Andrea Kienle Gabriele Kunau Kai-Uwe Loser Natalja Menold Concepts for usable patterns of groupware applications. 349-358 2003 conf/group/2003 GROUP http://doi.acm.org/10.1145/958160.958216 db/conf/group/group2003.html#HerrmannHJKKLM03