Heinz Ulrich Hoppe Karin Ammersbach Barbara Lutes-Schaab Gaby Zinßmeister EXPRESS: An Experimental Interface for Factual Information Retrieval. 63-81 1990 SIGIR db/conf/sigir/sigir90.html#HoppeALZ90 conf/sigir/90 SIGIR1990/P063.pdf db/conf/sigir/HoppeALZ90.html