This type of data analytical ecosystem has potential for wider implementation in related studies and other bibliographies. Open availability of the raw data as well as the analysis methods is central for efficient, collaborative, and transparent research use of bibliographic collections in modern society. We hope that open availability of data and methods, such as the ones released in this project, can pave the way towards open availability of the library catalogues. In some other fields of science, open data availability has already been established as a standard research practice. For instance, the human genome sequencing project and subsequent research programs have critically relied on open data sharing as well as the vast body of open source algorithms that have been collaboratively developed by the research community [REFS]. We have released a notably improved version of the Finnish national bibliography FNB. As such, we hope that our work is setting an example of a dedicated open science project, which aims to open the complete research workflow for collaborative criticism and development. 
Whereas our current work is based on the analysis of national catalogues, it is helping to challenge the nationalistic view of individual catalogues, and paves the way towards large-scale data integration. A number of key challenges remain to be overcome, however, in enhancing data quality. However, we have demonstrated that significant historical trends, such as the rate of change in language use or book sizes are often overwhelmingly clear and seen across multiple independently collected catalogues. Integrative analysis can thus help to verify the information and provide complementary views to the universally observed historical trends. Our systematic approach provides a starting point, guidelines, and a set of practically tested algorithms for more extensive analysis and integration.