1. P. Zeller, H. Gutmann, B. Hegedüs, A. Kaiser, A. Langemann, andM. Müller, Exper.19, 129 (1963).
2. A. Rutishauser andW. Bollag, Exper.19, 131 (1963).
3. K. Berneis, M. Kofler, W. Bollag, A. Kaiser, andA. Langemann, Exper.19, 132 (1963).
4. G. Weitzel, F. Schneider, andA.-M. Fretzdorf, Exper.20, 38 (1964).
5. W. Bollag, personal communication (1964).