1 January 1988 - 1 January 1991
| DOI | https://doi.org/10.48597/VPUJ-M2VK |
|---|---|
| Start time | 1 January 1988 |
| Stop time | 1 January 1991 |
| DOI | https://doi.org/10.48597/F3N9-4SWZ |
|---|---|
| Start time | 1 January 1988 |
| Stop time | 1 January 1990 |
| DOI | https://doi.org/10.48597/HWPQ-UJEJ |
|---|---|
| Start time | 1 January 1988 |
| Stop time | 1 January 1989 |