diff --git a/Source/Modules/LangModelRelated/mgrLangModel.swift b/Source/Modules/LangModelRelated/mgrLangModel.swift
index c82329d6..7e4df687 100644
--- a/Source/Modules/LangModelRelated/mgrLangModel.swift
+++ b/Source/Modules/LangModelRelated/mgrLangModel.swift
@@ -1,4 +1,6 @@
 // Copyright (c) 2021 and onwards The vChewing Project (MIT-NTL License).
+// Refactored from the ObjCpp-version of this class by:
+// (c) 2011 and onwards The OpenVanilla Project (MIT License).
 /*
 Permission is hereby granted, free of charge, to any person obtaining a copy of
 this software and associated documentation files (the "Software"), to deal in