docs/ctty.htm: add a useful URL to

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

diff --git a/docs/ctty.htm b/docs/ctty.htm
index 8f466cdde6677c2fff3113d2aed8b06293a01fa4..e7d2877f80ca17493c24db96f27e43cdd773158a 100644 (file)
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@@ -9,6 +9,8 @@
 
 <p>Before looking at the Linux implementation, first a general Unix
 description of threads, processes, process groups and sessions.
+</p><p>
+(See also <a href="http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap11.html">General Terminal Interface</a>)
 </p><p>A session contains a number of process groups, and a process group
 contains a number of processes, and a process contains a number
 of threads.