1. Hood, L.L. Geophys. Res. Lett. 14, 844–847 (1987).
2. Lin, R.P., El-Baz, F., Hood, L.L., Runcorn, S.K. & Schultz, P. Lunar planet. Sci. XI, 626–627 (1980).
3. Srnka, L.J. Proc. 8th Lunar Sci. Conf. 782–795 (1977).
4. Cisowski, S.M., Dunn, J.R., Fuller, M., Rose, M.F. & Wasilewski, P. Proc. 5th Lunar Sci. Conf. 2841–2858 (1974).
5. Dyal, P., Parkin, C.W. & Sonett, C.P. Apollo 12, Prelimi-nary Sci. Rep. NASA Spec. Publ. 235, 55–73 (1970).