New reference intervals for thyrotropin and thyroid hormones based on National Academy of Clinical Biochemistry criteria and regular ultrasonography of the thyroid - Kratzsch, J; Fiedler, G M; Leichtle, A; Brugel, M; Buchbinder, S; Otto, L; Sabri, O; Matthes, G; Thiery, J (Clin Chem, 2005)