title: Recursively find files with a specific extension
body: <p>I'm trying to find files with specific extensions. 
  For example, I want to find all .pdf and .jpg files that's named Robert</p>
  
  <p>I know I can do this command </p>
  
  <pre><code>$ find . -name '*.h' -o -name '*.cpp'
  </code></pre>
  
  <p>but I need to specify the name of the file itself besides the extensions. 
  I just want to see if there's a possible way to avoid writing the file name again and over again
  Thank you !</p>