1. Baldauf, W. and Balfanz, U., in Energy from Biomass Thermochemical Conversion, ed. A. V. Bridgwater and G. Grassi. Procedure of the EC Contractors' Meeting, 29–31 October 1991, Gent, Belgium, p. 147.
2. Laurent, E., Maggi, R. and Delmon, B., in Proceedings of the 8th European Conference on Biomass for Energy and Environment Agriculture and Industry, Vol. 2, ed. Ph. Chartier, A. A. C. M. Beenackers and G. Grassi, Vienna, 3–5 October 1994. Pergamon, Oxford, 1995, p. 1485.
3. Samolada, M. C. and Vasalos, I. A., in Developments in Thermochemical Biomass Conversion, Vol. 1, ed. A. V. Bridgwater and G. B. Boococke. Proceedings of the International Conference, 20–24 May 1996, Banff, Canada. Blackie Acad. and Prof., 1997, p. 657.
4. Chen, N. Y., Walsh, D. E. and Koening, L. R., in Pyrolysis Oils from Biomass, ed. J. Soltes and T. A. Milne. ACS Symp. Series 376, 1988, p. 277.
5. Catalytic upgrading of pyrolysis oil