The Preparation and Assay of a Christmas Factor (Factor IX) Concentrate and its Use in the Treatment of two Patients - Biggs, Rosemary; Bidwell, Ethel; Handley, D. A; Macfarlane, R. G; Trueta, J; Elliot-Smith, A; Dike, GWR; Ash, B. J (Brit. J. Haemat., 1961)