1. A simple phenylalanine method for the detection of phenylketonuria in large populations of newborn infants;Guthrie;Pediatrics,1963
2. R. Guthrie, H. Tieckelmann, The inhibition assay: Its use in screening urinary specimens for metabolic differences associated with mental retardation (Proceedings of the London Conference/Scientific Study of Mental Deficiency. May and Baker Ltd. 1962 672-77).
3. Observed range of assay values for plasma and cerebrospinal fluid ammo acid levels in infants and children aged 3 months to 10 years;Applegarth;Clin Biochem,1979
4. An ultramicro automated method (auto analyser) for the fluorometric determination of phenylalanine;Ambrose;Tech Symp.,1967