1. Kuenen, Ph. H., Sci. Amer., April 1960.
2. Sorby, H. C., Quart. J. Geol. Soc. London, 36, 58 (1880).
3. Dawkins, W. B., Geol. Mag., 45, 466 (1908).
4. Kuenen, Ph. H., in Deltaic and Shallow Marine Deposits, edit. by van Straaten, L., 210 (Elsevier, Amsterdam, 1964).
5. Nemecz, E., Acta Geol. Acad. Sci. Hung., 6, 119 (1959).