1. D. O. Hall, Solar Energy22, 307–328 (1979); Nature278, 114–117 (1979); Outlook Agriculture10, 246–254 (1980).
2. D. O. Hall, Solar energy through biology-fuel for the future, in: Advances in food producing systems for arid and semi-arid lands, pp. 105–137. Ed. J. T. Manassah and E. J. Briskey. Academic Press, New York 1980.
3. M. Slesser and C. W. Lewis, Biological energy resources. Spon, London 1979. 196 pp.
4. V. Smil and W. E. Knowland, Energy in the developing world: the real energy crisis. Oxford Univ. Press, Oxford 1980. 300 pp.
5. Solar Energy: a UK assessment 1976. UK-ISES, 19 Albermarle Street, London W1, UK, 1976. 375 pp.