1. Slack, J. M. W., Holland, P. W. H. & Graham, C. F. Nature 361, 490–492 (1993).
2. Schram, F. R. & Ellis, W. N. Cladistics 10, 331–337 (1994).
3. Swofford, D. L. PAUP: Phylogenetic Analysis Using Parsimony, Version 3.1.1 (Illinois Natural History Survey, Champaign, Illinois, 1993).
4. Naito, M., Ishiguro, H., Fujisawa, T. & Kurosawa, Y. FEBS Lett. 333, 271–274 (1993).
5. Schummer, M., Scheurlen, I., Schaller, C. & Galliot, B. EMBO J. 11, 1815–1823 (1992).