title: Can internal classes be accessed within other namespaces?
body: <p>I'm currently reading this book online:
  <a href="http://www.angelfire.com/theforce/chewy0/csharp/Thinking_in_C-Sharp_.pdf" rel="nofollow noreferrer">http://www.angelfire.com/theforce/chewy0/csharp/Thinking_in_C-Sharp_.pdf</a></p>
  
  <p>On page 23 (38 of the PDF document) it states that <strong>internal</strong> classes cannot be accessed from classes within external <em>namespaces</em>.</p>
  
  <p>However, in the online Microsoft documentation it states that <strong>internal</strong> classes are only accessible from the same <em>assembly</em>.</p>
  
  <p><a href="https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/internal" rel="nofollow noreferrer">https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/internal</a></p>
  
  <p>From my understanding, an <em>assembly</em> can contain classes from multiple <em>namespaces</em>. 
  Would this not mean from the Microsoft documentation that <strong>internal</strong> classes could be accessed across different <em>namespaces</em>?  </p>
  
  <p>Or is it true to say that <strong>internal</strong> classes are private within both of their respected <em>assemblies</em> and <em>namespaces</em>?</p>