The protocol implementation OAI_PMH PUMA provides access to metadata and the "full-text 'of documents made available by the authors in" OpenAccess ".
The service is available at URL: http://pumaoai.isti.cnr.it and creates a simple but powerful tool for international dissemination of research products in the Puma.
The service is accessed regularly by specialized portals such as:
OpenAIRE "OpenAIRE has been used as a source for data to measure the 'impact' of Horizon2020 so far. Open Access is a vital part of that..." ;
OAIster "A catalog of over 25 million records representing digital resources from more than 1,100 employees."