El factor Rh. 

 - Madrid  Santaolalla  [1973] 
 - 64 p.  illus. 
<br/><br/><label>LCCN: </label>73593942  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Rh-Hr Blood-Group System--popular works.
<br/><br/><label>National Library of Medicine Call No.: </label>W6  / P3 v.7429