00270nam a2200109 a 450000500170000002000150001708200130003210000140004524500440005926000300010330000270013320251203110931.0  a8181280474  a512bCOH  aCohn. P.M  aBasic AlgebrabGroups, rings and fields  aNew DelhibSpringerc2003  axiic465p.c24 cm.cPB