SELECT
  d.DEP_NAME, sq.LAB_CNT
FROM DEPARTAMENT d,

  (SELECT
    d.DEP_ID, COUNT(*) AS LAB_CNT
  FROM
    LABORING l,
    DEPARTAMENT d
  WHERE l.DEP_ID = d.DEP_ID
    GROUP BY d.DEP_ID
  HAVING COUNT(*) <= 3) sq

WHERE d.DEP_ID = sq.DEP_ID