1 January 1990 - 1 January 1991
| DOI | https://doi.org/10.48597/2TT4-AM7G |
|---|---|
| Start time | 1 January 1990 |
| Stop time | 1 January 1991 |
| DOI | https://doi.org/10.48597/ZABB-YTMS |
|---|---|
| Start time | 1 January 1989 |
| Stop time | 1 January 1990 |
| DOI | https://doi.org/10.48597/74CY-PF2E |
|---|---|
| Start time | 1 January 1988 |
| Stop time | 1 January 1989 |
| DOI | https://doi.org/10.48597/TZMH-E8ZP |
|---|---|
| Start time | 1 January 1997 |
| Stop time | 1 January 1998 |
| DOI | https://doi.org/10.48597/Y23X-GUSB |
|---|---|
| Start time | 1 January 1987 |
| Stop time | 1 January 1988 |