1. 1) Takagi H. and Nakagawa M. : Japan Tappi J. in press
2. 2) Hrutfiord B.F. and Negri A.R. : TAPPI J. 73 (6) 219-225 (1990)
3. 3) Dallons V.J., Hoy D.R., Messmer R.A. and Crawford R.J. : Tappi J. 73 (6) 91-95 (1990)
4. 4) Crawford R.J., Dallons V.J., Jain A.K. and Jett S.W. : Tappi J. 74 (4) 159-163 (1991)
5. 5) NCASI technical bulletin No. 585 (1990)