Zehna, Peter W. <br/><br/>
Elements of set theory / 
Peter W. Zehna, Robert L. Johnson. 
 - Boston :  Allyn and Bacon,  c1962. 
 - xiv, 194 p. : ill. 
 - College mathematics series .
<br/><br/><label>Subjects--Topical Terms: </label><br/>Set theory.