| Abbreviation | Definition |
|---|---|
| NTRL | National Technical Report Library |
| NTRL | National Technical Reports Library |
| NTRL | National Tuberculosis Reference Library |
| NTRL | Northern Tier Regional Library |
| NTUL | National Taiwan University Libraries |
| NUML | Northwestern University Medical Library |
| NYAM | New York Academy of Medicine |
| NYAS | New York Academy of Science |
| NYLA | New York Library Association |
| NYLINE | New York's Libraries Information Network |
| NYPL | New York Public Library |
| NYSL | New York Society Library |
| NYSL | New York State Library |
| NYT | New York Times |
| NYW | New York World |
| NZMedJ | New Zealand Medical Journal (Dunedin) |
| o/w | otherwise |
| OAC | Online Archive of California |
| OAI | Open Archives Initiative |
| OAPEN | Open Access Publishing in European Networks |