--- a/src/compiler/hppa/cell.lisp
+++ b/src/compiler/hppa/cell.lisp
@@ -157,6 +157,8 @@
 ;;; BIND -- Establish VAL as a binding for SYMBOL.  Save the old value and
 ;;; the symbol on the binding stack and stuff the new value into the
 ;;; symbol.
+;;;
+;;; See the "Chapter 9: Specials" of the SBCL Internals Manual.
 
 (define-vop (bind)
   (:args (val :scs (any-reg descriptor-reg))