diff --git a/Documentation/Models/Book/entities.ent b/Documentation/Models/Book/entities.ent
index a99e657..d3b1984 100644
--- a/Documentation/Models/Book/entities.ent
+++ b/Documentation/Models/Book/entities.ent
@@ -6,16 +6,6 @@
     their maintainance easier to realize.
 -->
 
-<!-- Common document structure -->
-
-<!ENTITY preface                SYSTEM "Preface.docbook">
-<!ENTITY preface-docconvs       SYSTEM "Preface/docconvs.docbook">
-<!ENTITY preface-feedback       SYSTEM "Preface/feedback.docbook">
-
-<!ENTITY licenses               SYSTEM "Licenses.docbook">
-<!ENTITY licenses-gpl           SYSTEM "Licenses/gpl.docbook">
-<!ENTITY licenses-gfdl          SYSTEM "Licenses/gfdl.docbook">
-
 <!-- About Corporate Identity -->
 
 <!ENTITY CI         "Corporate Identity">