1. Recommendation of the International Commission for Radiological Units, Radiology,62, 106 (1954),
2. ICRU, Report 11, Washington (1968).
3. ICRU, Report 19, Washington (1971).
4. Radiation Safety, Quantities, Units, Methods, and Instruments, Reports 19 and 20 of the ICRU (1974).
5. Comite Consultatif pour les etalons de mesures des radiations ionisantes. 4th Session (1963); 5th Session (1964).