diff --git a/lib/damask/orientation.py b/lib/damask/orientation.py
index f34f33a53..9d14d12c5 100644
--- a/lib/damask/orientation.py
+++ b/lib/damask/orientation.py
@@ -999,7 +999,8 @@ class Orientation:
     if relationModel not in ['KS','GT','GTdash','NW','Pitsch','Bain']:  return None
     if int(direction) == 0:  return None
 
-    # KS from S. Morito et al./Journal of Alloys and Compounds 5775 (2013) S587-S592 DOES THIS PAPER EXISTS?
+    # KS from S. Morito et al./Journal of Alloys and Compounds 5775 (2013) S587-S592
+    # for KS rotation matrices also check  K. Kitahara et al./Acta Materialia 54 (2006) 1279-1288
     # GT from Y. He et al./Journal of Applied Crystallography (2006). 39, 72-81
     # GT' from Y. He et al./Journal of Applied Crystallography (2006). 39, 72-81
     # NW from H. Kitahara et al./Materials Characterization 54 (2005) 378-386