Untitled

only select the row if the field value is unique
SELECT * FROM tbl
WHERE pk_artikel_id IN
  (SELECT MIN(pk_artikel_id) AS id FROM tbl GROUP BY fk_artikel_bron)

SELECT *
FROM  tbl
  JOIN (
    SELECT
      fk_artikel_bron,
      MIN(pk_artikel_id) AS id
    FROM tbl
    GROUP BY fk_artikel_bron) mins ON tbl.pk_artikel_id = mins.id

SELECT * from tbl t1
LEFT JOIN tbl t2
  ON t2.fk_artikel_bron = t1.fk_artikel_bron
  AND t2.pk_artikel_id < t1.pk_artikel_id
WHERE t2.pk_artikel_id IS NULL

select *
...
group by pk_artikel_bron

select * from (
    select *
    ...
    order by pk_artikel_id) x
group by pk_artikel_bron