1. M. Bucciolini, et al., Phys. Med. XV(2) (1999) 71.
2. AAPM TG. 21. Med. Phys. 10 (1983) 741.
3. ICRU. Report 49, ICRU Publications, Bethesda, MD, 1993.
4. G. Cuttone, et al., Phys. Med. XV(3) (1999) 121.
5. A.J.J. Bos, et al., IRI-CIEMAT Report 131-93-005, IRI, Delft.