Billings, Evelyn L., <br/><br/>
Mengenal metode ovulasi Billings / 
Evelyn L. Billings. 
 - 20 pages :  colour illustrations ;  21 cm. 
<br/><br/>
<br/><br/><label>ISBN: </label>9789792113846  hadiah 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Ovulation.<br/>Family planning.<br/>Menstrual cycle.<br/>Human reproduction--Endocrine aspects.