| U20 World Cup 1983 in Mexiko - Appearances as Referee |  |
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 |
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| 05/06/1983 | South Korea | - | Mexico | 2:1 | - | - | - |
| 15/06/1983 | South Korea | - | Brazil | 1:2 | 2 | - | - |
| U20 World Cup 1983 in Mexiko - Appearances as Referee | |
|
|
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| 05/06/1983 | South Korea | - | Mexico | 2:1 | - | - | - |
| 15/06/1983 | South Korea | - | Brazil | 1:2 | 2 | - | - |
| Complete name: | Johannes Nicolaus Ignacius Keizer |
| Born: | 06/10/1940 † 18/11/2024 |
| Place of birth: |
Volendam, 
Netherlands |
| Nationality: |
Netherlands |