Sikorski, R. <br/><br/>
Boolean algebras.-3rd ed. 
R. Sikorski 
 - 3rd ed. 
 - New york:  Springer,   1969. 
 - x, 237p. 
<br/><br/><label>Subjects--Index Terms: </label>Boolean algebras. 
<br/><br/><label>Universal Decimal Class. No.: </label>512.563  / SIK