Added \label{} for logical addressing.
diff --git a/Doc/lib/libsgi.tex b/Doc/lib/libsgi.tex
index 8deede8..b1bb5cb 100644
--- a/Doc/lib/libsgi.tex
+++ b/Doc/lib/libsgi.tex
@@ -1,4 +1,5 @@
 \chapter{SGI IRIX Specific Services}
+\label{sgi}
 
 The modules described in this chapter provide interfaces to features
 that are unique to SGI's IRIX operating system (versions 4 and 5).