oai-pmh.md

@@ -59,6 +59,7 @@ For the element langstring the attribute xml:lang is used.
 - https://standards.ieee.org/standard/1484_12_3-2020.html
 - https://oer-repo.uibk.ac.at/lom/latest/
 - https://www.data.gv.at/katalog/dataset/stat_ofos-2012
+- https://www.doi.org/
 - https://creativecommons.org/
 - https://www.openeducation.at/
 - https://oerhub.at/
\ No newline at end of file