Downing, Douglas <br/><br/>
Trigonometry, the easy way / 
by Douglas Downing. 
 - 2nd ed. 
 - New York :  Barron's Educational Series,  1990. 
 - ix, 310 p. :  ill. 
<br/><br/> Includes index 
<br/><br/><label>ISBN: </label>0812043898 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Trigonometry