diff --git a/README.md b/README.md
index 59a6002..cdd93d8 100644
--- a/README.md
+++ b/README.md
@@ -35,10 +35,10 @@
         + **導讀** 第三章 [Getting started with neural networks][17]
             + Katy Chou
         + **補充** [But what *is* a Neural Network? | Deep learning, chapter 1][18]
-            + Gomax 推薦
-        + **補充** [How Deep Neural Networks Work][19]
-            + Roger 推薦
-    - [x] 第四週 10/13 10/12
+            + Gomax
+        + **補充** [How Deep Learning Neural Network Works][55]
+            + Roger
+    - [ ] 第四週 10/13 10/12
         + **導讀** 第四章 [Fundamentals of machine learning][20]
             + Noah Chen
     - [x] 第五週 10/20 10/19
@@ -94,11 +94,11 @@
     + Enzo 推薦
 + **Fb粉絲頁** [ccClub][54] & Medium:[Coding & Co-working Club][53]
     + Winni 推薦
-+ **書籍** [練好機器學習的基本功][55]
++ **書籍** [練好機器學習的基本功][56]
     + Winni 推薦
-+ **Google** [Google機器學習資源1:Prerequisites and Prework][56]
-+ **Google** [Google機器學習資源2:Machine Learning Crash Course][57]
-+ **Google** [Google機器學習資源3:Path of Machine Learning][58]
++ **Google** [Google機器學習資源1:Prerequisites and Prework][57]
++ **Google** [Google機器學習資源2:Machine Learning Crash Course][58]
++ **Google** [Google機器學習資源3:Path of Machine Learning][59]
     + Winni 推薦
 
 
@@ -144,8 +144,10 @@
 [52]:http://moocs.nccu.edu.tw/course/132/section/lecture
 [53]:https://medium.com/ccclub
 [54]:https://www.facebook.com/ccclub.io/?__xts__%5B0%5D=68.ARCnhjk8stSyaFt_vriAHC14KT_e9rrZyhmEmIeymdpbi1DLM-wgJVITp3zXb9dRjT6aK95i-mgLRi8bG-ezFy7hunCpy-ZGYC0GkJEPvTmfjm5yOXlYXO7_0tUsMCv-h3SUlOdVvc63dyU8T7HpL2tktySLN0dLGl1AjfR0o4ZRyvplknijGkEYuWVqyacA4FkOfpqO2jBUxnC4psEQp4Vp1lI-F621xi71ssw
-[55]:https://www.books.com.tw/products/0010797283
-[56]:https://developers.google.com/machine-learning/crash-course/prereqs-and-prework?fbclid=IwAR0UUErHm9a1BmT2X8MKoiV0P8eVdfIomiN-Oq7W-ZazWAMzwHsjMjbS0is
-[57]:https://developers.google.com/machine-learning/crash-course/?utm_source=DevRel&utm_medium=StudyJam&utm_campaign=q1y2018&utm_term&utm_content=mlcc&fbclid=IwAR2EypJlNex4cxn_uL8QwRbK2GVS2PNrRQGYWv9L54IQLqkx83QSs39xT_k
-[58]:https://techdevguide.withgoogle.com/paths/machine-learning/
+[55]:https://www.youtube.com/watch?v=ILsA4nyG7I0&feature=youtu.be&t=852
+[56]:https://www.books.com.tw/products/0010797283
+[57]:https://developers.google.com/machine-learning/crash-course/prereqs-and-prework?fbclid=IwAR0UUErHm9a1BmT2X8MKoiV0P8eVdfIomiN-Oq7W-ZazWAMzwHsjMjbS0is
+[58]:https://developers.google.com/machine-learning/crash-course/?utm_source=DevRel&utm_medium=StudyJam&utm_campaign=q1y2018&utm_term&utm_content=mlcc&fbclid=IwAR2EypJlNex4cxn_uL8QwRbK2GVS2PNrRQGYWv9L54IQLqkx83QSs39xT_k
+[59]:https://techdevguide.withgoogle.com/paths/machine-learning/
+