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       new method for structural optimization</em>. International journal for
       numerical methods in engineering, 24 (2):359–373, 1987.
     <li><a name="2"></a>E. Kuci, F. Henrotte, P. Duysinx, and C. Geuzaine.
-      <em>Design sensitivity analysis for shape optimization based on the Lie
-      derivative</em>. Computer Methods in Applied Mechanics and Engineering 317
-      (2017), pp. 702 –722.
+      <em><a href="http://www.montefiore.ulg.ac.be/~geuzaine/preprints/preprint_sensitivity_lie.pdf">Design
+      sensitivity analysis for shape optimization based on the Lie
+      derivative</a></em>. Computer Methods in Applied Mechanics and Engineering
+      317 (2017), pp. 702 –722.
   </ol>
 </div>