diff --git a/.gitmodules b/.gitmodules
deleted file mode 100644
index 6e01eb75..00000000
--- a/.gitmodules
+++ /dev/null
@@ -1,4 +0,0 @@
-[submodule "doc/PythonRoboticsPaper"]
-	path = paper/PythonRoboticsPaper
-	url = https://github.com/AtsushiSakai/PythonRoboticsPaper
-
diff --git a/paper/.gitkeep b/paper/.gitkeep
deleted file mode 100644
index e69de29b..00000000