S. Haas, and E. Grams. Proceedings of the third ACM conference on Digital libraries, page 99--107. Pittsburgh, Pennsylvania, United States, ACM Press, (June 1998)
M. Haas, M. Lew, and D. Huijsmans. Image Databases and Multi-Media Search, volume 8 of Series on Software Engineering and Knowledge Engineering, WorldScientific, (1998)