Towards Federated Search Based on Web Services. - Jens Graupmann; Michael Biwer; Patrick Zimmer (BTW, 2003)

The BINGO! System for Information Portal Generation and Expert Web Search. - Sergej Sizov; Martin Theobald; Stefan Siersdorfer; Gerhard Weikum; Jens Graupmann; Michael Biwer; Patrick Zimmer (CIDR, 2003)

COMPASS: A Concept-based Web Search Engine for HTML, XML, and Deep Web Data. - Jens Graupmann; Michael Biwer; Christian Zimmer 001; Patrick Zimmer; Matthias Bender 001; Martin Theobald; Gerhard Weikum (VLDB, 2004)