title: Php regex to remove duplicated words
body: <p>I have string:</p>
  
  <pre><code>$s = 'Артгалерея Живопись Африка и от the Albert$Lizah, L-77, Christ UF1.1 (Christ).';
  </code></pre>
  
  <p>I wish to receive in a array the next string:</p>
  
  <pre><code>$s = 'Артгалерея Живопись Африка Albert Lizah Christ';
  </code></pre>
  
  <p>I used regex:</p>
  
  <pre><code>   preg_match_all('#\pL{4,}+#iu', $s, $m);
     $m = preg_replace("/\b(\w+)\s+\\1\b/i", "$1", implode(' ',$m[0]));
     $m = explode(' ', $m);
     echo '&lt;pre&gt;'.print_r($m, 1).'&lt;/pre&gt;';
  </code></pre>
  
  <p>And received:</p>
  
  <pre><code>$s = 'Артгалерея Живопись Африка Albert Lizah Christ Christ';
  </code></pre>
  
  <p>But I can not receive a string without duplicating words.</p>
  
  <p><strong>Question</strong>: How to change regular expression php - '#\pL{4,}+#iu', to exclude inclusion in a string of duplicating words?</p>
  
  <p>Thank you very much!</p>