1. Lorenzini, G. (1993),Medit 4(2), 53–59.
2. Heggestad, H. E. (1991),Environ. Pollut. 74, 264–291.
3. Taylor, G. S. (1974),Phytopath. 64, 1047,1048.
4. Howell, R. K. and Kremer, D. F. (1972),J. Environ. Qual. 1, 94–97.
5. Lorenzini, G. (1992), inBiological Indicators for Environmental Monitoring, Bonotto, S., Nobili, R., and Revoltella, R. P., eds., Serono Symposia, Rome, pp. 47–63.