title: Linq Where value is in Array
body: <pre><code>IEnumerable&lt;string&gt; periods = new string[] {"ABC", "JKD", "223A"};
  
  var someData = from p in returns  
                 from d in p.ReturnDet  
                 where p.Year &gt; 2009 
                 where d.Period &lt;is in periods array&gt; 
  </code></pre>
  
  <p>How do I select values where the d.periods are contained in the periods array?</p>