diff --git a/.gitmodules b/.gitmodules
index 3565aca4dde772a55a38aaaa7dbca0b8c083f6c7..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -1,6 +0,0 @@
-[submodule "hugo/book/themes/book"]
-	path = hugo/book/themes/book
-	url = https://github.com/alex-shpak/hugo-book
-[submodule "hugo/anotherbook/themes/book"]
-	path = hugo/anotherbook/themes/book
-	url = https://github.com/alex-shpak/hugo-book
diff --git a/hugo/anotherbook/themes/book b/hugo/anotherbook/themes/book
deleted file mode 160000
index 8f64ee74aa1dbefa452c824830956abc405a7787..0000000000000000000000000000000000000000
--- a/hugo/anotherbook/themes/book
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 8f64ee74aa1dbefa452c824830956abc405a7787
diff --git a/hugo/book/themes/book b/hugo/book/themes/book
deleted file mode 160000
index 8f64ee74aa1dbefa452c824830956abc405a7787..0000000000000000000000000000000000000000
--- a/hugo/book/themes/book
+++ /dev/null
@@ -1 +0,0 @@
-Subproject commit 8f64ee74aa1dbefa452c824830956abc405a7787
diff --git a/notebooks/.gitkeep b/notebooks/.gitkeep
new file mode 100644
index 0000000000000000000000000000000000000000..e69de29bb2d1d6434b8b29ae775ad8c2e48c5391