diff --git a/book/external/Nested-Books b/book/external/Nested-Books
index c0aab87..15f59b1 160000
--- a/book/external/Nested-Books
+++ b/book/external/Nested-Books
@@ -1 +1 @@
-Subproject commit c0aab87a87c97e2c643c4e905a0065a49d925616
+Subproject commit 15f59b176f793e457df3f44842f3d2b1631c3a9e
diff --git a/book/external/Sphinx-Grasple-public b/book/external/Sphinx-Grasple-public
index 4158a9c..b809233 160000
--- a/book/external/Sphinx-Grasple-public
+++ b/book/external/Sphinx-Grasple-public
@@ -1 +1 @@
-Subproject commit 4158a9c5cc5b299496066fa3fe36b569814c5f2b
+Subproject commit b8092330480b6b4694e91f100af4824becd77db2
diff --git a/book/external/TeachBooks b/book/external/TeachBooks
index ba87520..1beb447 160000
--- a/book/external/TeachBooks
+++ b/book/external/TeachBooks
@@ -1 +1 @@
-Subproject commit ba8752053a5a4c70d8dacc77e65433f5bfb5a318
+Subproject commit 1beb4478a5f7df378d99f19e651f41d85fd7961c