Billings, Evelyn. <br/><br/>
The Billings method  controlling fertility without drugs or devices 
Evelyn Billings & Ann Westmore. 
 - New York  Random House  c1980. 
 - 254 p.  ill. 
<br/><br/> Includes index. 
<br/><br/>Bibliography: p. [230]-237. 
<br/><br/><label>ISBN: </label> 12.95 
<br/><br/><label>LCCN: </label>81050275 //r82 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Natural family planning.--Ovulation method.