Courant Richard <br/><br/>
What is mathematics   An elementary approach to ide    
Courant Richard; Robbins Herbert 
 - Oxford  Oxford University Press          1941 
 - 521p  cm. 
<br/><br/> Appendix p 487-514 
<br/><br/><label>Source: </label> General Book 
<br/><br/><label>Dewey Class. No.: </label>B, H1