Gelfand, S.I. <br/><br/>
Homological algebra   
by Gelfand S.I. 
 - Berlin  S.V  1999 
 - 222p. 
<br/><br/><label>ISBN: </label>3540653783 
<br/><br/><label>Dewey Class. No.: </label>512.55  / N99