Billings, J J <br/><br/>
Ovulation method of contraception.  [electronic resource] 

 -  The Medical journal of Australia  Jan 1981 
 - 45-6 p.  digital 
<br/><br/> Publication Type: Letter 
<br/><br/><label>ISSN: </label>0025-729X 
<br/><br/><label>Standard No.: </label>10.5694/j.1326-5377.1981.tb135299.x  doi 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Female<br/>Humans<br/>Natural Family Planning Methods