diff --git a/ch11_blockchain.adoc b/ch11_blockchain.adoc
index f8ede214..e6c5c1da 100644
--- a/ch11_blockchain.adoc
+++ b/ch11_blockchain.adoc
@@ -421,7 +421,7 @@ image::images/mbc3_1102.png["merkle_tree"]
 Because the merkle tree is a binary tree, it needs
 an even number of leaf nodes. If there are an odd number of transactions
 to summarize, the last transaction hash will be duplicated to create an
-even number of leaf nodes, also known as a _balanced tree_. This is
+even number of leaf nodes, also known ((("balanced trees")))as a _balanced tree_. This is
 shown in <<merkle_tree_odd>>, where transaction C is duplicated.
 Similarly, if there are an odd number of hashes to process at any level,
 the last hash is duplicated.