Rock, John Charles <br/><br/>
Control de natalidad 
John Charles Rock ; traducción de R.B. Costa. 
 - Barcelona  Seix Barral  1964. 
 - 195 p. 
<br/><br/> Translation of : The time has come. 
<br/><br/>Includes bibliographies. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Birth control--United States.