DBIS lists databases licensed from ZB MED as well as databases freely available on the internet (subject bibliographies, factual databases, full text databases etc.). You will find an overview of the different types of access here.
If you select the appropriate subject area, you will find an extensive range of options for researching bibliographies and other sources. In the advanced search you can narrow down your search according to further criteria. Within a subject database, you then often have sophisticated options for formulating your research.
Click here for Databases (DBIS).