National audienceThis article aims to demonstrate the importance of producing retrospective national bibliographies, particularly in France, where, unlike other countries, no such bibliography exists. A comprehensive census of printed documents in library collections would shed light on little-known aspects of our heritage, as well as providing a remarkable resource for researchers and an excellent platform for highly accurate catalogue entries. A retrospective bibliography would also be a key tool in document management and a point of access to digitised collections. As such, it must be undertaken not only in France, but Europe-wide.Cet article a pour objet de montrer l'utilité de réaliser des bibliographies nationales rétrospectives, nota...