Cospar space research. 14, Proceedings of open meetings of working groups of the sixteenth plenary meeting of COSPAR, Constance, F.R.G., 23 May-5 June 1973 and resumés of the Symposium on Noctilucent Clouds and Intrplanetary Dust, Constance, F.R.G., 24 and 25 May 1973 - Reasenberg, R. D.; Rycroft, Michael J. (Berlin : Akademie-Verlag, 1974)