Halmos, Paul R.  1916-2006. <br/><br/>
A Hilbert space problem book / 
Paul R. Halmos. 
 - 2nd ed., rev. and enl. ed. 
 - New York [etc.] :  Springer-Verlag,  1982. 
<br/><br/><label>ISBN: </label>0387906851 
<br/><br/><label>Universal Decimal Class. No.: </label>51