1. Brasier, M.D. et al. Geol. Mag. 127, 319–332 (1990).
2. Berger, W.H., Smetacek, V.S. & Wefer, G. Productivity of the Ocean: Present and Past. (Wiley, Chichester, 1989).
3. Droser, M. & Bottjer, D.J. Abstr. 28th Int. geol. Congr., Washington 1, 418–419 (1989).
4. Cowie, J.W. & Brasier, M.D. (eds) The Precambrian-Cambrian boundary. (Oxford University Press, 1989).
5. Zhuravlev, A. Geol. Mag. 123, 377–385 (1986).