1. Belgium, 1963. Royal Decree of 28/2/1963 and modifications
2. Bruggeman, M., Gerits, J., Mandoki, R., Carchon, R., 1998. The low level waste assay system Q2: accuracy and detection limits. Internal Report SCK-CEN R-3271
3. Limits for qualitative detection and quantification determination;Curie;Analytical Chemistry,1968
4. DIN, 1989. DIN 25482 Tcil 1. Nachweisgrenze und Erkennungsgrenze bei Kernstrahlungs-messungen
5. IAEA, 1988. Principles for the exemption of radiation sources and practices from regulatory control. Safety Guides, Safety Series No. 89