1. Barnett, J. R., N. Z. Jl For. Sci., 1 (2), 208–222 (1971).
2. Barnett, J. R., Ann. Bot., 37, 1005–1011 (1973).
3. Dansgaard, W., in Symposium on Stable Isotopes and the Water Cycle, (IUGG, Berkeley, 1963).
4. Green, J. W., in Methods in Carbohydrate Chemistry, III (edit. by Whistler, R. L.), (Academic, London, 1963).
5. Craig, H., Science, 133, 1833–1834 (1961).