1. Zheng, G.-H., Jing, X.-M. & Tao, K.-L.Nature 393, 223–224 (1998).
2. Ellis, R. H., Hong, T. D. & Roberts, E. H. Ann. Bot. 57, 499–503 (1986).
3. Ellis, R. H. & Roberts, E. H. Ann. Bot. 45, 13–30 (1980).
4. Ellis, R. H., Hong, T. D. & Roberts, E. H. Ann. Bot. 69, 53–58 (1992).
5. Annual Report 1991 (International Board for Plant Genetic Resources, Rome, 1992).