1. Libeer JC. External Quality Assessment in Clinical Laboratories: European perspectives today and tomorrow. PhD thesis, University of Antwerp; 1993.
2. US Department of Health and Human Services. Medicare, Medicaid and CLIA programs: regulations implementing the Clinical Laboratory Improvement Amendments of 1988 (CLIA), final rule. Fed Reg. 1992;7002–7186.
3. NCCLS Guidelines: Preliminary evaluation of clinical chemistry methods. Doc EP10-T, 1989.
4. NCCLS Guidelines: Evaluation of precision performance of clinical chemistry devices. EP5–T2, 1992.
5. NCCLS Guidelines: Evaluation of linearity of quantitative analytical methods. EP6-P, 1986.