| Europa League 1972/1973 - Appearances as Referee |  |
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| 26/09/1972 | Grasshopper Club Zürich | - | Nîmes Olympique | 2:1 | 1 | - | - |
| Europa League 1972/1973 - Appearances as Referee | |
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| 26/09/1972 | Grasshopper Club Zürich | - | Nîmes Olympique | 2:1 | 1 | - | - |
| Complete name: | Johannes Nicolaus Ignacius Keizer |
| Born: | 06/10/1940 † 18/11/2024 |
| Place of birth: |
Volendam, 
Netherlands |
| Nationality: |
Netherlands |