| Youth Bundesliga West 2019/2020 - Appearances as Referee |  |
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 |
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| 11/08/2019 | Bor. Mönchengladbach | - | FC Schalke 04 | 2:1 | 4 | - | - |
| 25/08/2019 | VfL Bochum | - | Wuppertaler SV | 3:1 | 4 | - | - |
| 27/10/2019 | MSV Duisburg | - | Bor. Mönchengladbach | 1:2 | 4 | - | - |
| Youth Bundesliga West 2019/2020 - Appearances as Referee | |
|
|
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| 11/08/2019 | Bor. Mönchengladbach | - | FC Schalke 04 | 2:1 | 4 | - | - |
| 25/08/2019 | VfL Bochum | - | Wuppertaler SV | 3:1 | 4 | - | - |
| 27/10/2019 | MSV Duisburg | - | Bor. Mönchengladbach | 1:2 | 4 | - | - |
| Complete name: | David Markus Koj |
| Born: | 26/09/1993 |
| Place of birth: |
Germany |
| Residence: | Wegberg |
| Nationality: |
Germany |
| Profession: | Beisitzer |
| Club: | Sportclub Wegberg 1912 |