1. Banin, A. and Lahav, N.: 1968,Nature 217 1146.
2. Banin, A. and Paecht-Horowitz, M.: 1980, Statement in Report to NASA, Grant No. NG 33-006-070.
3. Brack, A. and Spach, G.: 1980, in ‘Origin of Life’, Y. Wolman (ed.),Proceed. 3rd ISSOL Meeting, Jerusalem, D. Reidel, Publ., Dordrecht, p. 487.
4. Cocking, E.C. and Yemm, E.W.: 1955,The Analyst 80 209.
5. Eirich, F.R.: 1979, Report to NASA Grant No. NG 33-006-070.