000 00325nam a2200121Ia 4500
008 240531s9999 xx 000 0 und d
020 _a330800495
082 _a523 1 OPE
100 _aOPEN University
245 0 _aUnderstanding space and time : Cosmology, block 5, units 13 & 17
260 _aO. U. P
_b1979
942 _cANF
999 _c317365
_d317365