What is mathematical logic? / 
J.N. Crossley... [et. al.]. 
 - New York :  Dover Publications,  c1990. 
 - 82p. 
<br/><br/><label>ISBN: </label>0-48626404-1 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Logic, symbolic and mathematical.