Velleman. J. D. <br/><br/>
How to prove it/  A structured approach 
Daniel, V. J. 
 - Cambridge  Cambridge university press  1994 
 - ix, 309p, ;ill  hbk 
<br/><br/><label>ISBN: </label>0521441161 
<br/><br/><label>LC Class. No.: </label>QA9.V38 1994