From 1920 onwards, there were several attempts to identify, systematically arrange and bibliographically record the literature references on the Rhineland. Unfortunately, none of these regional bibliographies lasted. It was not until 1983 that the North Rhine-Westphalia Bibliography began to provide consistent access to the regional literature on the northern Rhineland. Nevertheless, the older regional bibliographies on the Rhineland are a useful backward supplement to the North Rhine-Westphalia Bibliography.
For searching older, especially dependent literature on the Rhineland, important historical regional bibliographies from the holdings of the ULB Düsseldorf have been digitized and are conveniently searchable in full text via the Digital Collections.