1. Gibson, A. H. Somiplan Symp. Kuala Lumpur (1976).
2. McCree, K. J. in Prediction and Measurement of Photosynthetic Productivity (ed. Setlik, I.) 221–229 (Pudoc, Wageningen, 1970).
3. Thornley, J. H. M. Mathematical Models in Plant Physiology (Academic, New York, 1976).
4. Pirt, S. J. Proc. R. Soc. B 163, 224–231 (1965).
5. Penning de Vries, F. W. T. in Crop Processes in Controlled Environments (ed. Rees et al.) (Academic, New York, 1972).