diff --git a/src/renderer_d3d11.cpp b/src/renderer_d3d11.cpp
index bb9b3fee..a09c9ecc 100644
--- a/src/renderer_d3d11.cpp
+++ b/src/renderer_d3d11.cpp
@@ -487,6 +487,8 @@ namespace bgfx { namespace d3d11
 		return false;
 	};
 
+	// Reference:
+	// https://github.com/GPUOpen-LibrariesAndSDKs/AGS_SDK
 	enum AGS_RETURN_CODE
 	{
 		AGS_SUCCESS,