,   . <br/><br/>
Nature  Vol . 343,344,345,346,347,348  Textual Documents 

 -  1990. 
 - 590 ;    
<br/><br/><label>ISBN: </label>  
<br/><br/><label>Subjects--Index Terms: </label>Medicine  Medical Science 
<br/><br/><label>Dewey Class. No.: </label>616