Merge pull request #610 from JinShil/patch-1

"Book" link now points to "Books" wiki page

doc.ddoc

@@ -188,10 +188,8 @@ $(NAVBLOCK_HEADER $(TOCHEADERL index.html, D Programming Language, D $(LATEST)),
     $(TOCENTRYT http://digitalmars.com/d/1.0/index.html, D Programming Language 1.0, D1 Home)
 )
 $(NAVBLOCK_HEADER $(TOCHEADER Documentation),
-    $(TOCENTRY http://qznc.github.io/d-tut/, Tutorial)
-    $(LI $(AMAZONLINK 0321635361, Book))
-    $(TOCENTRY http://www.informit.com/articles/article.aspx?p=1381876, &nbsp;<font size=-1><span style="visibility: hidden">3</span>1.&nbsp;Tutorial</font>)
-    $(TOCENTRY http://www.informit.com/articles/article.aspx?p=1609144, &nbsp;<font size=-1>13.&nbsp;Concurrency</font>)
+    $(TOCENTRY http://ddili.org/ders/d.en/index.html, Online Book (free))
+    $(TOCENTRYT http://wiki.dlang.org/Books, D Programming Language Books, More Books)
 
     $(TOCENTRYH language-reference.html, Language Reference, $(CATEGORY_SPEC $(SUBNAV_SPEC)))
     $(TOCENTRY phobos/index.html, Library Reference)