title: Regex in Java: match groups until first symbol occurrence
body: <p>My string looks like this:</p>
  
  <pre><code>"Chitkara DK, Rawat DJY, Talley N. The epidemiology of childhood recurrent abdominal pain in Western countries: a systematic review. Am J Gastroenterol. 2005;100(8):1868-75. DOI."
  </code></pre>
  
  <p>What I want is to get letters in uppercase (as separate words only) until first dot, to get: <code>DK DJY N</code>. But not other characters after, like <code>J DOI</code>.</p>
  
  <p>Here`s my part of code for Java class Pattern: </p>
  
  <pre><code>\\b[A-Z]{1,3}\\b
  </code></pre>
  
  <p>Is there a general option in regex to stop matching after certain character?</p>