Sensitive immunoradiometric assay (IRMA) for serum thyrotropin may be insufficient to make the thyrotropin-releasing factor test unnecessary - Rodriquez-Espinosa, J; Ordonez-Llanos, J; Mora-Brugues, J; Lopez-Callul, C; Cortes-Rius, M (Clin Chem, 1985)