| KNVB beker 1968/1969 - Appearances as Referee |  |
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 |
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| 15/09/1968 | AGOVV | - | Feijenoord | 0:5 | - | - | - |
| 09/03/1969 | AFC Ajax | - | Feijenoord | 1:2 | - | - | - |
| 04/06/1969 | Feijenoord | - | DWS Amsterdam | 3:1 | - | - | - |
| KNVB beker 1968/1969 - Appearances as Referee | |
|
|
||||
| 15/09/1968 | AGOVV | - | Feijenoord | 0:5 | - | - | - |
| 09/03/1969 | AFC Ajax | - | Feijenoord | 1:2 | - | - | - |
| 04/06/1969 | Feijenoord | - | DWS Amsterdam | 3:1 | - | - | - |
| Complete name: | Wilhelmus Jacobus Maria Schalks |
| Born: | 21/03/1923 † 25/10/2017 |
| Place of birth: |
Leiden, 
Netherlands |
| Residence: | Leiden |
| Nationality: |
Netherlands |