```cmake
# Insight Journal Handle: https://hdl.handle.net/10380/3460
# Contact: Alexander Schmidt-Richberg <a.schmidt-richberg@imperial.ac.uk>
#          Jan Ehrhardt <ehrhardt@imi.uni-luebeck.de>
#          Rene Werner <r.werner@uke.de>
itk_fetch_module(VariationalRegistration
  "A module to perform variational image registration. https://hdl.handle.net/10380/3460"
  GIT_REPOSITORY ${git_protocol}://github.com/VariationalRegistration/VariationalRegistration.git
  GIT_TAG 71bf23a2ad4b4c0924d3cf041cafa3d617f02f32
  )
```

Update VariationalRegistration to address Doxygen warnings
user
```cmake
# Insight Journal Handle: https://hdl.handle.net/10380/3460
# Contact: Alexander Schmidt-Richberg <a.schmidt-richberg@imperial.ac.uk>
#          Jan Ehrhardt <ehrhardt@imi.uni-luebeck.de>
#          Rene Werner <r.werner@uke.de>
itk_fetch_module(VariationalRegistration
  "A module to perform variational image registration. https://hdl.handle.net/10380/3460"
  GIT_REPOSITORY ${git_protocol}://github.com/InsightSoftwareConsortium/ITKVariationalRegistration.git
  GIT_TAG da4acc1804e36b8f5b0fcf7179bddcf98679c6d3
  )
```
assistant