diff --git a/container_windows.c b/container_windows.c
index ec7b4bd8..8c4f4595 100644
--- a/container_windows.c
+++ b/container_windows.c
@@ -55,7 +55,7 @@ BOOL sharedWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam, LRESULT *
 	return FALSE;
 }
 
-// TODO get source
+// from https://msdn.microsoft.com/en-us/library/windows/desktop/dn742486.aspx#sizingandspacing
 #define winXPadding 4
 #define winYPadding 4
 
diff --git a/window_windows.c b/window_windows.c
index cb0bffbd..20fbbd9b 100644
--- a/window_windows.c
+++ b/window_windows.c
@@ -12,7 +12,7 @@ struct uiWindow {
 
 #define uiWindowClass L"uiWindowClass"
 
-// TODO get source
+// from https://msdn.microsoft.com/en-us/library/windows/desktop/dn742486.aspx#sizingandspacing
 #define windowMargin 7
 
 static LRESULT CALLBACK uiWindowWndProc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam)