| Europa League 2021/2022 - Appearances as Referee |  |
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 |
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| 16/09/2021 | PSV Eindhoven | - | Real Sociedad | 2:2 | 7 | - | - |
| 09/12/2021 | Olympique Marseille | - | Lokomotiv Moskva | 1:0 | 6 | 1 | - |
| Europa League 2021/2022 - Appearances as Referee | |
|
|
||||
| 16/09/2021 | PSV Eindhoven | - | Real Sociedad | 2:2 | 7 | - | - |
| 09/12/2021 | Olympique Marseille | - | Lokomotiv Moskva | 1:0 | 6 | 1 | - |
| Complete name: | William Collum |
| Born: | 18/01/1979 |
| Place of birth: |
Glasgow, 
Scotland |
| Residence: | Motherwell |
| Nationality: |
Scotland |
| Profession: | Lehrer |
| Height: | 174 cm |
| Weight: | 69 kg |