diff --git a/ch06_transactions.adoc b/ch06_transactions.adoc
index 618bebaa..fc863923 100644
--- a/ch06_transactions.adoc
+++ b/ch06_transactions.adoc
@@ -781,7 +781,7 @@ problems with placing witnesses in the input script field.
 
 ==== Circular Dependencies
 
-Many contract protocols for Bitcoin involve a series of transactions
+Many ((("transactions", "witnesses", "circular dependencies", id="transaction-witness-circular")))((("witnesses", "circular dependencies", id="witness-circular")))((("circular dependencies", id="circular")))contract protocols for Bitcoin involve a series of transactions
 that are signed out of order.  For example, Alice and Bob want to
 deposit funds into a script that can only be spent with signatures from
 both of them, but they each also want to get their money back if the
@@ -807,7 +807,7 @@ txid for Tx~0~ is part of the input's outpoint in Tx~1~.  That means
 there's no way for Alice and Bob to construct Tx~1~ until both
 signatures for Tx~0~ are known--but if they know the signatures for
 Tx~0~, one of them can broadcast that transaction before signing the
-refund transaction, eliminating the guarantee of a refund.  This is a
+refund transaction, eliminating the guarantee of a refund.  This((("transactions", "witnesses", "circular dependencies", startref="transaction-witness-circular")))((("witnesses", "circular dependencies", startref="witness-circular")))((("circular dependencies", startref="circular"))) is a
 _circular dependency_.
 
 ==== Third-Party Transaction Malleability