1. Apostoli P, Alessio L (1992) Lead in the 1990's: ?new? regulations for the ?oldest? of environmental toxins. Med Lav 83:539?556
2. Araki S Katsuyuki M, Hirishi A (1987) Central and peripheral nervous system dysfunction in workers exposed to lead, zinc and copper. Int Arch Occup Environ Health 59:177?187
3. Beale EML (1969) Cluster analysis. Scientific Control System, London
4. Buchthal F, Behse F (1979) Electrophysiology and nerve biopsy in man exposed to lead. Br J Ind Med 36:135?147
5. Buceti R, Abbate C, Giorgianni C, Munaò F, Broccio A, Ferreri G (1993) Comportamento dei PEV e dell'EOG in soggetti professionalmente esposti al piombo. Boll Oculistica 72:53?62