diff --git a/ch12_mining.adoc b/ch12_mining.adoc
index a8e8f22f..1e6cdfb2 100644
--- a/ch12_mining.adoc
+++ b/ch12_mining.adoc
@@ -1243,7 +1243,7 @@ a rapid pace.
 [[extra_nonce]]
 ==== The Extra Nonce Solution
 
-Since 2012, mining has evolved to resolve a
+Since 2012, mining((("bitcoins", "mining", "extra nonce solution", id="bitcoin-mining-nonce")))((("mining", "extra nonce solution", id="mining-nonce")))((("extra nonce solution", id="extra-nonce"))) has evolved to resolve a
 fundamental limitation in the structure of the block header. In the
 early days of Bitcoin, a miner could find a block by iterating through
 the nonce until the resulting hash was below the target. As difficulty
@@ -1279,7 +1279,7 @@ an individual piece of mining equipment to perform up to 281 TH/s by
 only making changes to the block header.  This keeps mining equipment
 and protocols simpler than incrementing the extra nonce in the coinbase
 transaction every 4 billion hashes, which requires recalculating the
-entire left flank of the merkle tree up to the root.
+entire left flank of the merkle tree up to ((("bitcoins", "mining", "extra nonce solution", startref="bitcoin-mining-nonce")))((("mining", "extra nonce solution", startref="mining-nonce")))((("extra nonce solution", startref="extra-nonce")))the root.
 
 [[mining_pools]]
 ==== Mining Pools