diff --git a/fvnlib.f90 b/fvnlib.f90
index 8d81908..ebf84a7 100644
--- a/fvnlib.f90
+++ b/fvnlib.f90
@@ -19,7 +19,8 @@ module fvn
 !
 !
 ! This piece of code is totally free! Do whatever you want with it. However
-! if you find it usefull it would be kind to give credits ;-)
+! if you find it usefull it would be kind to give credits ;-) Nevertheless, you
+! may give credits to quadpack authors.
 !
 ! Version 1.1
 !