diff --git a/ch08_signatures.adoc b/ch08_signatures.adoc
index 8b67d6e3..6dd835d2 100644
--- a/ch08_signatures.adoc
+++ b/ch08_signatures.adoc
@@ -804,7 +804,7 @@ will become available after the publication of this((("digital signatures", "sch
 [[ecdsa_signatures]]
 === ECDSA Signatures
 
-Unfortunately for the future development of Bitcoin and many other
+Unfortunately ((("digital signatures", "ECDSA", id="digital-signature-ecdsa")))((("ECDSA (Elliptic Curve Digital Signature Algorithm)", id="ecdsa")))for the future development of Bitcoin and many other
 applications, Claus Schnorr patented the algorithm he discovered and
 prevented its use in open standards and open source software for almost
 two decades.  Cryptographers in the early 1990s who were blocked from
@@ -917,7 +917,7 @@ as follows:
   * +0x02+, another integer follows
   * +0x20+, the length of the integer (32 bytes)
   * +S+, ++4b9f039ff08df09cbe9f6addac960298cad530a863ea8f53982c09db8f6e3813++
-* A suffix (+0x01+) indicating the type of hash used (+SIGHASH_ALL+)
+* A suffix (+0x01+) indicating the type of hash((("digital signatures", "ECDSA", startref="digital-signature-ecdsa")))((("ECDSA (Elliptic Curve Digital Signature Algorithm)", startref="ecdsa"))) used (+SIGHASH_ALL+)
 
 [[nonce_warning]]
 === The Importance of Randomness in Signatures