1. What is the quality of quality control procedures;De Verdier;Scand J Clin Lab Invest,1981
2. Quality control-how much is enough?;Guy;Transfusion,1977
3. Analytical goals in clinical chemistry: their relationship to medical care;Elevitch;Am J Clin Pathol,1979
4. National immunohaematology proficiency survey (NIPS);Austin;NZ J Med Lab Technol,1981
5. The UK national external quality assessment scheme in blood group serology Compatibility testing 1979-1980;Holburn;Clin Lab Haematol,1982