| U20 World Cup 1983 in Mexiko - Appearances as Assistant | ||||
| 03/06/1983 | South Korea | - | Scotland | 0:2 |
| 09/06/1983 | Mexico | - | Scotland | 0:1 |
| 11/06/1983 | Uruguay | - | South Korea | 1:2 aet |
| U20 World Cup 1983 in Mexiko - Appearances as Assistant | ||||
| 03/06/1983 | South Korea | - | Scotland | 0:2 |
| 09/06/1983 | Mexico | - | Scotland | 0:1 |
| 11/06/1983 | Uruguay | - | South Korea | 1:2 aet |
| Complete name: | Johannes Nicolaus Ignacius Keizer |
| Born: | 06/10/1940 |
| Place of birth: |
Volendam, 
Netherlands |
| Nationality: |
Netherlands |