Scientific American 261 

 - New York  Sciam  Dez. 1989 
 - 106 
 - 20100702 
 - Scientific American  261 .
<br/><br/><label>ISSN: </label>1679-656X 
<br/><br/><label>Dewey Class. No.: </label>SAM 2010  / 2010