diff --git a/doc/dev-doc/CMakeLists.txt b/doc/dev-doc/CMakeLists.txt
index 19d69c279..35f27a4ea 100644
--- a/doc/dev-doc/CMakeLists.txt
+++ b/doc/dev-doc/CMakeLists.txt
@@ -1,191 +1,196 @@
 set(DOXYGEN_INPUT_DOX ${CMAKE_CURRENT_BINARY_DIR}/akantu.dox)
 set(DOXYGEN_XML_DIR ${CMAKE_CURRENT_BINARY_DIR}/xml)
 set(DOXYGEN_OUTPUT ${DOXYGEN_XML_DIR}/index.xml)
 
 # configured documentation tools and intermediate build results
 set(BINARY_BUILD_DIR "${CMAKE_CURRENT_BINARY_DIR}/_build")
 # Sphinx cache with pickled ReST documents
 set(SPHINX_CACHE_DIR "${CMAKE_CURRENT_BINARY_DIR}/_doctrees")
 # HTML output directory
 set(SPHINX_HTML_DIR "${CMAKE_CURRENT_BINARY_DIR}/html")
 set(SPHINX_OUTPUT "${SPHINX_HTML_DIR}/index.html")
 
 # ---------------------------------------------------------------------------- #
 # Doxygen                                                                      #
 # ---------------------------------------------------------------------------- #
 find_package(Doxygen REQUIRED)
 
 set(DOXYGEN_WARNINGS NO)
 set(DOXYGEN_QUIET YES)
 if(CMAKE_VERBOSE_MAKEFILE)
   set(DOXYGEN_WARNINGS YES)
   set(DOXYGEN_QUIET NO)
 endif(CMAKE_VERBOSE_MAKEFILE)
 
   package_get_all_source_files(
     AKANTU_LIBRARY_SRCS
     AKANTU_LIBRARY_PUBLIC_HDRS
     AKANTU_LIBRARY_PRIVATE_HDRS
     )
 
 package_get_all_include_directories(
   _akantu_include_dirs
   )
 
 package_get_all_external_informations(
   PRIVATE_INCLUDE AKANTU_PRIVATE_EXTERNAL_INCLUDE_DIR
   INTERFACE_INCLUDE AKANTU_INTERFACE_EXTERNAL_INCLUDE_DIR
   LIBRARIES AKANTU_EXTERNAL_LIBRARIES
   )
 
 list(APPEND _akantu_include_dirs
   ${AKANTU_PRIVATE_EXTERNAL_INCLUDE_DIR}
   ${AKANTU_INTERFACE_EXTERNAL_INCLUDE_DIR}
   ${PROJECT_BINARY_DIR}/src)
 
 
 file(STRINGS ${PROJECT_SOURCE_DIR}/.clang-format AKANTU_TAB_SIZE
   REGEX "^TabWidth: *([0-9]*)"
   )
 string(REGEX REPLACE ".*([0-9]+)" "\\1" AKANTU_TAB_SIZE "${AKANTU_TAB_SIZE}")
 
 if (CMAKE_VERSION VERSION_GREATER 3.9.5)
   #set(DOXYGEN_WARNINGS YES)
   #set(DOXYGEN_QUIET NO)
   set(DOXYGEN_STRIP_FROM_PATH ${PROJECT_SOURCE_DIR})
   set(DOXYGEN_STRIP_FROM_INC_PATH ${PROJECT_SOURCE_DIR})
   set(DOXYGEN_TAB_SIZE ${AKANTU_TAB_SIZE})
   set(DOXYGEN_ALIASES
     "rst=\\verbatim embed:rst"
     "endrst=\\endverbatim"
     )
   set(DOXYGEN_WARN_IF_UNDOCUMENTED NO)
   set(DOXYGEN_WARN_IF_DOC_ERROR NO)
   set(DOXYGEN_WARN_AS_ERROR NO)
   set(DOXYGEN_EXCLUDE  "${PROJECT_SOURCE_DIR}/src/common/aka_fwd.hh")
   set(DOXYGEN_RECURSIVE YES)
   set(DOXYGEN_EXCLUDE
     "aka_named_argument.hh"
     )
   set(DOXYGEN_EXAMPLE_PATH "${PROJECT_SOURCE_DIR}/examples")
   set(DOXYGEN_EXAMPLE_RECURSIVE YES)
   set(DOXYGEN_SOURCE_BROWSER NO)
   set(DOXYGEN_CLANG_ASSISTED_PARSING NO)
   #set(DOXYGEN_CLANG_OPTIONS          )
   set(DOXYGEN_CLANG_DATABASE_PATH ${CMAKE_BINARY_DIR})
   set(DOXYGEN_USE_MATHJAX YES)
   set(DOXYGEN_GENERATE_HTML NO)
   set(DOXYGEN_GENERATE_HTMLHELP NO)
   set(DOXYGEN_GENERATE_LATEX NO)
   set(DOXYGEN_GENERATE_XML YES)
   set(DOXYGEN_XML_OUTPUT xml)
   set(DOXYGEN_ENABLE_PREPROCESSING YES)
   set(DOXYGEN_MACRO_EXPANSION YES)
   set(DOXYGEN_INCLUDE_PATH ${_akantu_include_dirs})
 #  set(DOXYGEN_PREDEFINED
 #    ${AKANTU_DEFINITIONS}
 #    "DOXYGEN"
 #    "AKANTU_TO_IMPLEMENT()="
 #    "DECLARE_NAMED_ARGUMENT()="
 #    "OPTIONAL_NAMED_ARGUMENT(n, v)=v"
 #    "REQUIRED_NAMED_ARGUMENT(n)="
 #    )
   set(DOXYGEN_COLLABORATION_GRAPH NO)
   set(DOXYGEN_UML_LOOK YES)
   set(DOXYGEN_TEMPLATE_RELATIONS YES)
   set(DOXYGEN_CALL_GRAPH YES)
   set(DOXYGEN_CALLER_GRAPH YES)
   set(DOXYGEN_DOT_GRAPH_MAX_NODES 500)
   set(DOXYGEN_SHOW_FILES NO)
   set(DOXYGEN_LOOKUP_CACHE_SIZE 9)
 
   set(_SRCS
     ${AKANTU_LIBRARY_SRCS}
     ${AKANTU_LIBRARY_PUBLIC_HDRS}
     ${AKANTU_LIBRARY_PRIVATE_HDRS}
     )
 
   list(REMOVE_ITEM _SRCS
     "${PROJECT_SOURCE_DIR}/src/common/aka_named_argument.hh")
 
   doxygen_add_docs(doxygen-doc
     ${_SRCS}
     USE_STAMP_FILE
     COMMENT "Building XML documentation with Doxygen in ${DOXYGEN_XML_DIR}"
     )
 
 else()
   string(REGEX REPLACE ";" " " AKANTU_DOXYGEN_DEFINTIONS "${AKANTU_DEFINITIONS};DOXYGEN")
   string(REGEX REPLACE ";" " " AKANTU_DOXYGEN_INCLUDE_DIRS "${_akantu_include_dirs}")
 
   make_directory(${DOXYGEN_XML_DIR})
 
   configure_file(${CMAKE_CURRENT_SOURCE_DIR}/akantu.dox.in
     ${DOXYGEN_INPUT_DOX}
     )
 
   add_custom_command(
     OUTPUT ${DOXYGEN_OUTPUT}
     COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYGEN_INPUT_DOX}
     DEPENDS ${DOXYGEN_INPUT_DOX}
     COMMENT "Building XML documentation with Doxygen in ${DOXYGEN_XML_DIR}"
     )
 
   add_custom_target(doxygen-doc ALL
     DEPENDS ${DOXYGEN_OUTPUT}
     )
 
   add_custom_target(doxygen-doc-forced
     COMMAND ${DOXYGEN_EXECUTABLE} ${DOXYGEN_INPUT}
     COMMENT "Building XML documentation with Doxygen (forced) in ${DOXYGEN_XML_DIR}"
     )
 endif()
 # ---------------------------------------------------------------------------- #
 # Sphinx                                                                       #
 # ---------------------------------------------------------------------------- #
 find_package(Sphinx REQUIRED)
 
 set(SPHINX_VERBOSE_FLAG "-q")
 if(CMAKE_VERBOSE_MAKEFILE)
   set(SPHINX_VERBOSE_FLAG)
 endif(CMAKE_VERBOSE_MAKEFILE)
 
 # set(AKANTU_IN_READTHEDOC TRUE)
 # configure_file(
 #   "${CMAKE_CURRENT_SOURCE_DIR}/conf.py.in"
 #   "${CMAKE_CURRENT_SOURCE_DIR}/conf_rtd.py"
 #   @ONLY)
 
 set(AKANTU_IN_READTHEDOC FALSE)
 configure_file(
   "${CMAKE_CURRENT_SOURCE_DIR}/conf.py.in"
   "${CMAKE_CURRENT_BINARY_DIR}/conf.py"
   @ONLY)
 
+set(SPHINX_PARALLEL_FLAG)
+if (SPHINX_VERSION VERSION_GREATER_EQUAL 1.7.0)
+  set(SPHINX_PARALLEL_FLAG -j auto)
+endif()
+
 set(_sphinx_command ${SPHINX_BUILD_EXECUTABLE}
-  -j auto
+  ${SPHINX_PARALLEL_FLAG}
   ${SPHINX_VERBOSE_FLAG} -b html
   -c "${CMAKE_CURRENT_BINARY_DIR}"
   -d "${SPHINX_CACHE_DIR}"
   "${CMAKE_CURRENT_SOURCE_DIR}"
   "${SPHINX_HTML_DIR}"
   )
 
 file(GLOB_RECURSE _SPHINX_SRCS
   "*.rst")
 
 add_custom_command(
   OUTPUT ${SPHINX_OUTPUT}
   COMMAND ${_sphinx_command}
   DEPENDS doxygen-doc ${SPHINX_INPUT} ${_SPHINX_SRCS}
   COMMENT "Building HTML documentation with Sphinx in ${SPHINX_HTML_DIR}"
   )
 
 add_custom_target(sphinx-doc ALL
   DEPENDS ${SPHINX_OUTPUT})
 
 add_custom_target(sphinx-doc-forced
   COMMAND ${_sphinx_command}
   DEPENDS doxygen-doc
   COMMENT "Building HTML documentation with Sphinx (forced) in ${SPHINX_HTML_DIR}"
   )