Reference Linking
In some fields, e.g. Physics, publishers have linking agreements already in place.
Alternatives to DOI:
- PubMed/PubRef (National Library of Medicine)
- PubSCIENCE (DOE/OSTI)
- OpCit project
- Proprietary Link Managers (AIP, APS)
System design calls for one URL for each DOI; underlying technology can handle multiple URLs however.