[Answer]-Filtering on foreign keys

You are passing string to the foreign key’s primary key which is integer by default. If you want to filter based on foreign key field use

def get_queryset(self):
    return Article.objects.filter(foreignkey__valuefield=self.kwargs['value'])

Source
https://docs.djangoproject.com/en/dev/topics/db/queries/#filters-can-reference-fields-on-the-model