| Europa League 1965/1966 - Appearances as Referee |  |
 |
 |
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| 22/09/1965 | Chelsea FC | - | AS Roma | 4:1 | - | - | 1 |
| 27/10/1965 | Vålerenga IF | - | Heart of Midlothian | 1:3 | - | - | - |
| Europa League 1965/1966 - Appearances as Referee | |
|
|
||||
| 22/09/1965 | Chelsea FC | - | AS Roma | 4:1 | - | - | 1 |
| 27/10/1965 | Vålerenga IF | - | Heart of Midlothian | 1:3 | - | - | - |
| Complete name: | Wilhelmus Jacobus Maria Schalks |
| Born: | 21/03/1923 † 25/10/2017 |
| Place of birth: |
Leiden, 
Netherlands |
| Residence: | Leiden |
| Nationality: |
Netherlands |