Billings, J J <br/><br/>
Natural family planning.  [electronic resource] 

 -  Papua and New Guinea medical journal  Dec 1978 
 - 286-7 p.  digital 
<br/><br/> Publication Type: Editorial 
<br/><br/><label>ISSN: </label>0031-1480 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Australia<br/>Family Planning Services<br/>Female<br/>Humans<br/>Natural Family Planning Methods<br/>New Guinea<br/>Ovulation