000 00254nam a22000857a 4500
008 210301b ||||| |||| 00| 0 eng d
050 _aQC815 .H45
245 _aThe earth and its gravity field
_cHEISKANEN, W.A.
942 _2lcc
_hQC815 .H45 1958
999 _c1122
_d1122