1. Vidal, G. Geol. Unders. Rapp. 78, 1–18 (1976).
2. Bertrand-Sarfati, J. & Caby, R. Groenl. geol. Unders. Bull. 119, 1–51 (1976).
3. Golubic, S., Friedman, I. & Schneider, J. J. Sedim. Petrol. 51, 475–478 (1981).
4. Campbell, S. E. in Proc. 4th int. Symp. Biomineralization (eds Westbroek, P. & deJong, E. W.) (Reidel, Dordrecht, in the press).
5. Simone, L. Earth-Sci. Rev. 16, 319–355 (1980/81).