Ulrich’s Periodicals Directory is a bibliographic database providing detailed, comprehensive, and authoritative information on serials published throughout the world. It covers all subjects, and includes publications that are published regularly or irregularly and are circulated free of charge or by paid subscription. Ulrich’s was first published in 1932.

Zenodo is an open data repository, developed and operated by CERN. It is an catch-all repository, that welcomes research from all over the world, and from every discipline. Zenodo does not impose any requirements on format, size, access restrictions or licence. A digital object identifier (DOI) is automatically assigned to all Zenodo files and it is integrated into reporting for research funded by the European Commission.