1. FAO Forest Products Staistics: Pulp and Paper Production Capacities www.fao.org/forestry/statistics/81757/en/
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3. Chemical aspects of Kraft Pulping;Gierer;Wood Sci. Technol.,1980
4. Lignin Chemistry Past, Present and Future;Adler;Wood Sci. Technol.,1977
5. Modified continuous kraft pulping-now a reality;Johansson;Svensk Papperstidn.,1984