| KNVB beker 1969/1970 - Appearances as Referee |  |
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| 19/10/1969 | Hermes/DVS | - | SC Veendam | 2:0 | - | - | - |
| 01/03/1970 | Go Ahead | - | RBC Roosendaal | 3:0 | - | - | - |
| KNVB beker 1969/1970 - Appearances as Referee | |
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| 19/10/1969 | Hermes/DVS | - | SC Veendam | 2:0 | - | - | - |
| 01/03/1970 | Go Ahead | - | RBC Roosendaal | 3:0 | - | - | - |
| Complete name: | Johannes Nicolaus Ignacius Keizer |
| Born: | 06/10/1940 † 18/11/2024 |
| Place of birth: |
Volendam, 
Netherlands |
| Nationality: |
Netherlands |