title: SQLZOO Nobel Tutorial #8
body: <p><a href="http://sqlzoo.net/wiki/SELECT_from_Nobel_Tutorial" rel="nofollow">http://sqlzoo.net/wiki/SELECT_from_Nobel_Tutorial</a></p>
  
  <p><strong>Can someone give me some help</strong> to do the #8?<br>
  I am new to SQL, and I really have no idea why my answer is wrong:</p>
  
  <pre><code>select yr from nobel where 
  yr in (select distinct yr from nobel where subject='Physics') 
  and 
  yr not in (select distinct yr from nobel where subject='Chemistry')
  </code></pre>
  
  <p>Thanks</p>