diff --git a/book b/book
index c444859..09828b9 160000
--- a/book
+++ b/book
@@ -1 +1 @@
-Subproject commit c444859ccde9b18e2098a38d0af8a490f2ebe37e
+Subproject commit 09828b921387c7d599de18bff89b4fd73f822344