Solid Earth geophysics and satellite orbits : proceedings of Symposium 2 and of the Topical Meeting of the COSPAR Interdisciplinary Scientific Commission P (Meeting P1) of the COSPAR Twenty-sixth Plenary Meeting held in Toulouse, France, 30th June-11th July 1986 / edited by Ch. Reigber (Symp. 2), G. Balmino (Symp. 2) and B.A.C. Ambrosius (Topical Mtg P1)