db/conf/echt/StreitzHHLSST92.html Norbert A. Streitz Jörg M. Haake Jörg Hannemann Andreas C. Lemke Wolfgang Schuler Helge Schütt Manfred Thüring SEPIA: A Cooperative Hypermedia Authoring Environment. 11-22 ECHT1992/P011.pdf 1992 conf/echt/92 ECHT db/conf/echt/echt92.html#StreitzHHLSST92