Cubitt, Toby S <br/><br/>
The Un(solv)able Problem.  [electronic resource] 

 -  Scientific American  Sep 2018 
 - 28-37 p.  digital 
<br/><br/> Publication Type: Journal Article 
<br/><br/><label>ISSN: </label>0036-8733 
<br/><br/><label>Standard No.: </label>10.1038/scientificamerican1018-28  doi