RelatonDOI: retrieve Standards for bibliographic using DOI through Crossrefand provide Relaton object.

Relaton::Etsi: retrieve ETSI Standards for bibliographic using the BibliographicItem model

Relaton::Iana: Ruby XMLDOC impementation.

Relaton::Isbn: retrieve publications by ISBN for bibliographic use using the BibliographicItem model

Rendering of ISO 690 XML

Relaton::Xsf: retrieve ISO Standards for bibliographic use using the IsoBibliographicItem model