diff --git a/xd60.md b/xd60.md
index dc32e1b..15ca5c6 100644
--- a/xd60.md
+++ b/xd60.md
@@ -33,3 +33,8 @@
   ![LED Setting](img/TMK_keymap_Generator_04.png)
   5. 刷機 (刷機模式中) - 如果第一步驟所安裝的軟體都正確的話，應該可以看到像下圖一樣的情況，直接按下「寫入.eep檔案」就完成。
   ![flash firmware](img/TMK_keymap_Generator_05.png)
+
+
+### reference
+- [reddit](https://www.reddit.com/r/MechanicalKeyboards/comments/6pnpq7/xd64_layout_flashing_guide/)  
+- [massdrop](https://drop.com/buy/xd60-xd64-custom-mechanical-keyboard-kit/talk?sort=newest)
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