Leisenring, A. C. <br/><br/>
Mathematical logic and Hilbert's E-Symbol. 

 - New York :  Gordon & Breach,  [1969] 
 - University mathematical series .
<br/><br/>Bibliography: p. [129]-132. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Logic, Symbolic and mathematical.