1. Moilanen, A. and Sipilä, K., Optical properties of biomass chars in gasification. In Research in thermochemical biomass conversion, ed. Bridgewater, A. V. & Kuester, J. L., Elsevier Science Publisher, London and New York, 1988, pp. 355–369.
2. Bengtsson, M., Combustion behaviour for a range of coals of various origins and petrographic composition. Dissertation, The Royal Institute of Technology, Stockholm, Sweden, March 1986, 67 p. + app.
3. Vleeskens, J. M., van Haasteren, T. W. M. B., Roos, M. and Gerrits, J., Behaviour of different char components in fluidized bed combustion: a char petrography study. Fuel. 1988. 67. 3. 426–430.
4. Kojima, T., Yamashita, S., Adschiri, T. and Furusawa, T., Structural differences among chars produced at various heating rates and its effect on gasification rate of chars. In Proc. 1989 Int. Conf. on Coal Science, Oct. 23–27, 1989, Tokyo Japan, pp. 465–468.
5. Harris, D.J., Smith, I.W., Reactivity to carbon dioxide of petroleum coke, metallurgical coke and brown coal char. In Proc. 1989 Int. Conf. on Coal Science, Oct. 23–27, 1989, Tokyo Japan, pp. 301–304.