diff --git a/game-programmer-zh-cn.dot b/game-programmer-zh-cn.dot
index 44750a8..68a7a25 100644
--- a/game-programmer-zh-cn.dot
+++ b/game-programmer-zh-cn.dot
@@ -97,7 +97,7 @@ digraph {
         learntoprogramwithscratch [label=<<TABLE BORDER="0" CELLSPACING="0"><TR><TD WIDTH="100" HEIGHT="100" FIXEDSIZE="TRUE"><IMG SCALE="TRUE" SRC="images-zh-cn/learntoprogramwithscratch.jpg"/></TD></TR><TR><TD>动手玩转Scratch2.0编程 (2015)</TD></TR></TABLE>> URL="https://book.douban.com/subject/26658602/"]
         helpyoukidswithcomputercoding [label=<<TABLE BORDER="0" CELLSPACING="0"><TR><TD WIDTH="100" HEIGHT="100" FIXEDSIZE="TRUE"><IMG SCALE="TRUE" SRC="images/helpyoukidswithcomputercoding.jpg"/></TD></TR><TR><TD>Help Your Kids<br/>with Computer Coding<br/>(2015)</TD></TR></TABLE>> URL="https://www.amazon.com/dp/146541956X/"]
         
-        inventgamepython3 [label=<<TABLE BORDER="0" CELLSPACING="0"><TR><TD WIDTH="100" HEIGHT="100" FIXEDSIZE="TRUE"><IMG SCALE="TRUE" SRC="images/inventgamepython3.jpg"/></TD></TR><TR><TD>Invent Your Own<br/>Computer Games with<br/>Python 3rd Ed (2015)</TD></TR></TABLE>> URL="https://www.amazon.com/dp/1503212300/"]
+        inventgamepython4 [label=<<TABLE BORDER="0" CELLSPACING="0"><TR><TD WIDTH="100" HEIGHT="100" FIXEDSIZE="TRUE"><IMG SCALE="TRUE" SRC="images/inventgamepython4.jpg"/></TD></TR><TR><TD>Invent Your Own<br/>Computer Games with<br/>Python 4th Ed (2016)</TD></TR></TABLE>> URL="https://www.amazon.com/dp/1593277954/"]
         makinggamespython [label=<<TABLE BORDER="0" CELLSPACING="0"><TR><TD WIDTH="100" HEIGHT="100" FIXEDSIZE="TRUE"><IMG SCALE="TRUE" SRC="images/makinggamespython.jpg"/></TD></TR><TR><TD>Making Games with<br/>Python &amp; Pygame (2012)</TD></TR></TABLE>> URL="https://www.amazon.com/dp/1469901730/"]
         learntoprogramwithminecraft [label=<<TABLE BORDER="0" CELLSPACING="0"><TR><TD WIDTH="100" HEIGHT="100" FIXEDSIZE="TRUE"><IMG SCALE="TRUE" SRC="images/learntoprogramwithminecraft.jpg"/></TD></TR><TR><TD>Learn to Program<br/>with Minecraft (2015)</TD></TR></TABLE>> URL="https://www.amazon.com/dp/1593276702/"]
         adventuresinminecraft [label=<<TABLE BORDER="0" CELLSPACING="0"><TR><TD WIDTH="100" HEIGHT="100" FIXEDSIZE="TRUE"><IMG SCALE="TRUE" SRC="images-zh-cn/adventuresinminecraft.jpg"/></TD></TR><TR><TD>零基础学Minecraft编程<br/>(2015)</TD></TR></TABLE>> URL="https://book.douban.com/subject/26613247/"]
@@ -107,7 +107,7 @@ digraph {
         age8 -> codinggamesinscratch -> helpyoukidswithcomputercoding -> kidintermediate [arrowhead=normal, style=solid]
         age8 -> superscratchprogadv -> learntoprogramwithscratch -> kidintermediate
 
-        kidintermediate -> inventgamepython3 -> makinggamespython
+        kidintermediate -> inventgamepython4 -> makinggamespython
         kidintermediate -> learntoprogramwithminecraft -> adventuresinminecraft
         kidintermediate -> "3dgpforkids"