Durr, William K. Windley, Vivian O. Yates, Mildred C. <br/><br/>
Keystone. 

 - 1st Ed. 
 - Boston :  Houghton Mifflin Company,  1979. 
 - 576 p. 
<br/><br/><label>ISBN: </label>0395265940 
<br/><br/><label>Dewey Class. No.: </label>428.6  / DUR