Question: Richard Nieuwenhuizen served as a volunteer linesman at a youth football match in a city comprised of 6 what?
Sentence (from "Death of Richard Nieuwenhuizen"): The attack on him, for which six teenage players on the opposing team and one parent were subsequently convicted, and his death the following day have led to widespread protests and discussion in the Netherlands about violence associated with youth football, and continue to be an international example of the dangers of violence surrounding football matches.
Relevant evidence: No