1. Micro-Analysis in Medical Biochemistry;King, E.J.,1951
2. King, E. J., Yeoman, W. B. (1955). J. clin. Path., 8, 252.
3. From the Louis Jenner Laboratory, St. Thomas's Hospital and Medical School, and the Medical Research Council's Statistical Research Unit, London School of Hygiene and Tropical Medicine (RECEIVED FOR PUBLICATION JUNE 26, 1958)
4. have recently investigated some errors affecting Quick's prothrombin time. They found that the differences between the prothrombin times of normal persons were much greater than could be explained by the experimental error of the method, and that it was possible to devise a simple rule of thumb to express the amount by which a given " control" plasma might be expected to differ from another normal plasma;Armitage; Ingram,1958