Penrose, R <br/><br/>
Techniques of differential topology in relativity 
R. Penrose 
 - Philadelphia  SIAM  1972 
 - viii  72 
 - CBMS-NSF regional conference series in applied mathematic 7 .
<br/><br/><label>Dewey Class. No.: </label>13.06+7.04  / PENR