Washington, DC : Hemisphere Pub. Co., c1987-
| Archivage | Début | Fin |
|---|---|---|
| CLOCKSS Archive | 1987 | 2024 |
| CLOCKSS Archive | 2008 | 2017 |
| Internet Archive | 1987 | 1996 |
| Library of Congress | 2017 | 2023 |
| LOCKSS Archive | 1987 | 2024 |
| LOCKSS Archive | 2025 | 2025 |
| National Digital Preservation Program, China | 1997 | 2022 |
| National Library of the Netherlands | 1956 | 2008 |
| Portico | 1990 | 2025 |
| Scholars Portal | 1987 | 2022 |