1. ARPA Emilia Romagna, 1998. Environmental Radioactivity Network in the Emilia-Romagna Region. Results of 1998. Piacenza, Italy (in Italian).
2. Enhancement of natural radioactivity in soils and salt-marshes surrounding a non-nuclear industrial complex;Bolívar;The Science of the Total Environment,1995
3. The need for radiation controls in the phosphate and related industries;Boothe;Health Physics,1977
4. Brondi, M., Ferretti, O., Gragnani, R., Michetti, I., Paganin, G., Peroni, C., 1985. The radio-ecological survey carried out in the Po river, in the delta and in the facing Adriatic coast. In: Salento, N. (Ed.), National Conference on Radioactivity in the Environment, Piacenza, Italy, 27–28 June 1985, pp. 203–219 (in Italian).
5. Radioactivity in raw materials and end products in the Italian ceramics industry;Bruzzi;Journal of Environmental Radioactivity,2000