1. Berner, W., Oeschger, H. & Stauffer, B. Radiocarbon 22, 227–235 (1980).
2. Delmas, R. J., Ascencio, J.-M. & Legrand, M. Nature 284, 155–157 (1980).
3. Keeling, C. D. & Bacastow, R. B. in Energy and Climate 72–75 (National Academy of Sciences, Washington DC, 1977).
4. Stauffer, B., Berner, W., Oeschger, H. & Schwander, J. Zeitschrift für Gletscherk. Glazial-geol. 16, (in the press).
5. Zumbrunn, R. thesis, Univ. Bern (1981).