| Europa League 1979/1980 - Appearances as Referee |  |
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| 24/10/1979 | Lokomotiv Sofia | - | AS Monaco | 4:2 | - | - | - |
| Europa League 1979/1980 - Appearances as Referee | |
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|
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| 24/10/1979 | Lokomotiv Sofia | - | AS Monaco | 4:2 | - | - | - |
| Complete name: | Johannes Nicolaus Ignacius Keizer |
| Born: | 06/10/1940 |
| Place of birth: |
Volendam, 
Netherlands |
| Nationality: |
Netherlands |