check_key()
Check SHERPA/RoMEO API key
rr_api_version()
Return SHERPA/RoMEO API version
rr_auth()
Store provided API key into Environment Variable
Functions to access journals’ policies
rr_journal_find()
Find if journals are available in SHERPA/RoMEO
rr_journal_issn()
Retrieve journal policy using ISSN
rr_journal_name()
Retrieve journals policies by matching title
Functions to access information on publishers’ policies
rr_publisher_all()
Get all Publisher Policies
rr_publisher_continent()
Get Publisher Policy by Publisher's Continent
rr_publisher_country()
Get Publisher Policy by Publisher's Country
rr_publisher_id()
Get Publisher Policy from Publisher ID
rr_publisher_name()
Get Publisher Policy by Publisher Name
rr_romeo_colour()
Query publisher by RoMEO colour
