diff --git a/CMakeLists.txt b/CMakeLists.txt
index 7613cc1..20ba77d 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -23,7 +23,7 @@ include(cmake/CPM.cmake)
 CPMAddPackage(
   NAME PackageProject.cmake
   GITHUB_REPOSITORY TheLartians/PackageProject.cmake
-  VERSION 1.2
+  VERSION 1.2.1
 )
 
 # ---- Add source files ----
diff --git a/documentation/CMakeLists.txt b/documentation/CMakeLists.txt
index 064d295..5f9bf38 100644
--- a/documentation/CMakeLists.txt
+++ b/documentation/CMakeLists.txt
@@ -1,8 +1,6 @@
 cmake_minimum_required(VERSION 3.5 FATAL_ERROR)
 
-project(GreeterDocumentation
-  LANGUAGES CXX
-)
+project(GreeterDocs)
 
 # ---- Dependencies ----
 
@@ -24,7 +22,12 @@ CPMAddPackage(
 set(BUILD_DOCUMENTATION ON CACHE INTERNAL "")
 include(${StableCoder-cmake-scripts_SOURCE_DIR}/doxygen.cmake)
 
-# see https://github.com/StableCoder/cmake-scripts#doxygen-doxygencmake for options
+# set Doxyfile variables
+set(DOXYGEN_PROJECT_NAME Greeter)
+set(DOXYGEN_PROJECT_VERSION ${Greeter_VERSION})
+set(DOXYGEN_PROJECT_ROOT "${CMAKE_CURRENT_LIST_DIR}/..")
+
+# see https://github.com/StableCoder/cmake-scripts#doxygen-doxygencmake for additional options
 build_docs(
   TARGET_NAME GenerateDocs
   DOXYFILE_PATH ${CMAKE_CURRENT_LIST_DIR}/Doxyfile
diff --git a/documentation/Doxyfile b/documentation/Doxyfile
index d3207d2..24b8982 100644
--- a/documentation/Doxyfile
+++ b/documentation/Doxyfile
@@ -32,13 +32,13 @@ DOXYFILE_ENCODING      = UTF-8
 # title of most generated pages and in a few other places.
 # The default value is: My Project.
 
-PROJECT_NAME           = @PROJECT_NAME@
+PROJECT_NAME           = @DOXYGEN_PROJECT_NAME@
 
 # The PROJECT_NUMBER tag can be used to enter a project or revision number. This
 # could be handy for archiving the generated documentation or if some version
 # control system is used.
 
-PROJECT_NUMBER         = @PROJECT_VERSION@
+PROJECT_NUMBER         = @DOXYGEN_PROJECT_VERSION@
 
 # Using the PROJECT_BRIEF tag one can provide an optional one line description
 # for a project that appears at the top of each page and should give viewer a
@@ -823,7 +823,7 @@ WARN_LOGFILE           =
 # spaces. See also FILE_PATTERNS and EXTENSION_MAPPING
 # Note: If this tag is empty the current directory is searched.
 
-INPUT                  = @CMAKE_CURRENT_LIST_DIR@/../README.md @CMAKE_CURRENT_LIST_DIR@/../include
+INPUT                  = @DOXYGEN_PROJECT_ROOT@/README.md @DOXYGEN_PROJECT_ROOT@/include @DOXYGEN_PROJECT_ROOT@/source
 
 # This tag can be used to specify the character encoding of the source files
 # that doxygen parses. Internally doxygen uses the UTF-8 encoding. Doxygen uses
@@ -902,7 +902,7 @@ FILE_PATTERNS          = *.c \
 # be searched for input files as well.
 # The default value is: NO.
 
-RECURSIVE              = NO
+RECURSIVE              = YES
 
 # The EXCLUDE tag can be used to specify files and/or directories that should be
 # excluded from the INPUT source files. This way you can easily exclude a
@@ -1020,7 +1020,7 @@ FILTER_SOURCE_PATTERNS =
 # (index.html). This can be useful if you have a project on for instance GitHub
 # and want to reuse the introduction page also for the doxygen output.
 
-USE_MDFILE_AS_MAINPAGE = @CMAKE_CURRENT_LIST_DIR@/../README.md
+USE_MDFILE_AS_MAINPAGE = @DOXYGEN_PROJECT_ROOT@/README.md
 
 #---------------------------------------------------------------------------
 # Configuration options related to source browsing
@@ -1279,7 +1279,7 @@ HTML_DYNAMIC_MENUS     = YES
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-HTML_DYNAMIC_SECTIONS  = NO
+HTML_DYNAMIC_SECTIONS  = YES
 
 # With HTML_INDEX_NUM_ENTRIES one can control the preferred number of entries
 # shown in the various tree structured indices initially; the user can expand
@@ -1508,7 +1508,7 @@ DISABLE_INDEX          = NO
 # The default value is: NO.
 # This tag requires that the tag GENERATE_HTML is set to YES.
 
-GENERATE_TREEVIEW      = NO
+GENERATE_TREEVIEW      = YES
 
 # The ENUM_VALUES_PER_LINE tag can be used to set the number of enum values that
 # doxygen will group on one line in the generated HTML documentation.