Brad Mehlenbacher Beth Hardin Chris Barrett Jim Clagett Multi-user domains and virtual campuses: implications for computer-mediated collaboration and technical communication. 213-219 1994 conf/sigdoc/1994 SIGDOC http://doi.acm.org/10.1145/192506.192568 db/conf/sigdoc/sigdoc1994.html#MehlenbacherHBC94