Billings, John J. <br/><br/>
The Ovulation Method :  Natural Family Planning / 

 - Collegeville, Minn :  The Liturgical Press,  c1972. 
 - vi, 29 p. 
<br/><br/><label>ISBN: </label>0814610110 
<br/><br/><label>Dewey Class. No.: </label>259.12  / BIL