1 January 1990 - 1 January 1991
| DOI | https://doi.org/10.48597/A372-96Z5 |
|---|---|
| Start time | 1 January 1990 |
| Stop time | 1 January 1991 |
| DOI | https://doi.org/10.48597/YJW6-8JQ7 |
|---|---|
| Start time | 1 January 1989 |
| Stop time | 1 January 1990 |
| DOI | https://doi.org/10.48597/F6V4-NADM |
|---|---|
| Start time | 1 January 1988 |
| Stop time | 1 January 1989 |
| DOI | https://doi.org/10.48597/2FME-PQK9 |
|---|---|
| Start time | 1 January 1997 |
| Stop time | 1 January 1998 |
| DOI | https://doi.org/10.48597/K3QQ-AA4G |
|---|---|
| Start time | 1 January 1987 |
| Stop time | 1 January 1988 |