diff --git a/data/xml/traditions.xml b/data/xml/traditions.xml
index 83c5c74..6f97a98 100644
--- a/data/xml/traditions.xml
+++ b/data/xml/traditions.xml
@@ -126,7 +126,7 @@
 		</letterTradition>
 		
 		<letterTradition letter="20">
-			<app ref="">
+			<app ref="4">
 				Riga, Latvijas Akadēmiskā Bibliotekā, Ms. 1113, F. 25, V. 32, Nr. 33
 			</app>
 		</letterTradition>