diff --git a/SSTV.md b/SSTV.md
index 783bb31..e276a2a 100644
--- a/SSTV.md
+++ b/SSTV.md
@@ -20,4 +20,5 @@
 * Farbe: YCrCb
 * VIS-Code: 97
 * http://www.sstv-handbook.com/download/sstv_05.pdf
+* http://www.sstv-handbook.com/download/sstv_04.pdf <- Timings
 * http://www.classicsstv.com/pdmodes.php