ELAG 2017 Abstract: Authority files and identifiers are used by libraries to consistently refer to entities such as subjects and authors. This principle of referencing “things, not strings” is also applied successfully in Linked Open Data and knowledge bases. The open knowledge base Wikidata connects Wikipedia articles in any language and provides background information on article’s subject such images and affiliations. In addition to internal references Wikidata contains identifiers from more than thousand authority files: well known library identifiers such as VIAF and GND, researcher IDs such as ORCID and Google Scholar, and identifiers for many more items such as TED speakers and Find A Grave. Wikidata thus emerges as a giant curated linking hub based on authority identifiers. In contrast to closed authority files that often impose tedious procedures, Wikidata can be enhanced and corrected by anybody, just like Wikipedia. The management of links between authority files in Wikidata is particularly suitable for automation: mappings extracted from Wikidata can be used in other systems and mapping data is already available in libraries ready to be added to Wikidata. This presentation will illustrate the use of Wikidata as authority linking hub with a case study considering links between author identifiers from RePEc (Research Papers in Economics) and GND. Workflows include both automatic and semi-automatic mapping approaches. We will address both technical solutions and organizational policies ruling the operation of Wikidata bots for automated updates. The tools presented in this talk include “wdmapper” command line application for extracting and complementing mappings from Wikidata with external mapping files and the “Mix’n’Match” to support crowdsourced mapping of authority files to Wikidata. Online version: https://hackmd.io/s/S1YmXWC0e#