Digital research infrastructures for the humanities try to provide a working environment for scholars in the arts and humanities. One main concern is to facilitate access to existing collections in order to foster the reuse of these collections. The wide spectrum of available collections and the diverse information needs in this context brings up the requirement for retrieval applications supporting the discovery of interesting collections, a combined view over diverse collections, and in depth search in speci c collections. Obviously, this has to be supported on a heterogeneous set of collections speci cally tailored to the needs of scholars in the arts and humanities. The talk describes the scenario, presents approaches and prototypes, and discusses the challenges and limitations.