  This paper is a short description of an information retrieval system enhanced
by three model driven retrieval services: (1) co-word analysis based query
expansion, re-ranking via (2) Bradfordizing and (3) author centrality. The
different services each favor quite other - but still relevant - documents than
pure term-frequency based rankings. Each service can be interactively combined
with each other to allow an iterative retrieval refinement.
