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2. 2) Ministry of Environment, Government of Japan: "State of Discharge and Treatment of Industrial Waste in FY 2004", (2007).
3. 3) I. Abe: "Haikibutsu no Risaikuruhouhou ni Taisuru Ichiteian", Proceedings of the Annual Conference of the Japan Society of Waste Management Experts, 8 (1997) 206-208.
4. 4) K. Higuchi: Nihon Mokutanshi, Kodansya, (1978).