1. Approved recommendations (1978) on quality control in clinical chemistry. Part 1. General principles and terminology;Buttner;J Clin Chem Clin Biochem,1980
2. Approved recommendation (1978) on quality control in clinical chemistry
3. Approved recommendations (1979) on quality control in clinical chemistry. Part 3. Calibration and control materials;Buttner;J Clin Chem Clin Biochem,1980
4. Approved recommendation (1979) on quality control in clinical chemistry
5. Approved recommendation (1979) on quality control in clinical chemistry. Part 6. Quality requirements from the point of view of health care;Buttner;J Clin Chem Clin Biochem,1980