Smith, P A <br/><br/>
Permutable Periodic Transformations.  [electronic resource] 

 -  Proceedings of the National Academy of Sciences of the United States of America  May 1944 
 - 105-8 p.  digital 
<br/><br/> Publication Type: Journal Article 
<br/><br/><label>ISSN: </label>0027-8424 
<br/><br/><label>Standard No.: </label>10.1073/pnas.30.5.105  doi