diff --git a/ch12_mining.adoc b/ch12_mining.adoc
index 1abc824d..d6cdc8d1 100644
--- a/ch12_mining.adoc
+++ b/ch12_mining.adoc
@@ -303,7 +303,7 @@ address new types of denial-of-service attacks.
 
 By independently verifying each transaction as it is received and before
 propagating it, every node builds a pool of valid (but unconfirmed)
-transactions known ((("bitcoins", "mining", "independent transaction verification", startref="bitcoin-mining-verify")))((("mining", "independent transaction verification", startref="mining-verify")))((("transactions", "independent verification", startref="transaction-verify")))((("independent transaction verification", startref="independent-transaction-verify")))((("verifying", "transactions", startref="verify-transaction")))((("nodes", "transaction verification", startref="node-verify")))as the _memory pool_ or
+transactions known ((("bitcoins", "mining", "independent transaction verification", startref="bitcoin-mining-verify")))((("mining", "independent transaction verification", startref="mining-verify")))((("transactions", "independent verification", startref="transaction-verify")))((("independent transaction verification", startref="independent-transaction-verify")))((("verifying", "transactions", startref="verify-transaction")))((("nodes", "transaction verification", startref="node-verify")))((("memory pool")))as the _memory pool_ or
 _mempool_.
 
 === Mining Nodes