00432nam a2200133Ia 4500 260720b |||||||| |||| 00| 0 eng d 530.1 P417.TD Penrose, Roger 23630 Techniques of differential topology in relativity / Philadelphia: SIAM, 1972 viii, 72p. Regional conference series in Applied Mathematics ; 7 23631 ddc BK 0 0 0 530_100000000000000_P417_TD 0 20557 ISI ISI 1998-10-12 0 530.1 P417.TD DP16642 2019-02-14 00:00:00 BK 16863 16863