diff --git a/doc/src/sgml/book-decl.sgml b/doc/src/sgml/book-decl.sgml
deleted file mode 100644
index 61043a1b41..0000000000
--- a/doc/src/sgml/book-decl.sgml
+++ /dev/null
@@ -1,13 +0,0 @@
-<!doctype book PUBLIC "-//OASIS//DTD DocBook V3.1//EN" [
-
-<!entity % version SYSTEM "version.sgml">
-%version;
-<!entity % filelist SYSTEM "filelist.sgml">
-%filelist;
-
-<!entity % set-of-books "IGNORE">
-<!entity % single-book "INCLUDE">
-
-<!entity % entities SYSTEM "entities.sgml">
-%entities;
-]>
diff --git a/doc/src/sgml/refentry.sgml b/doc/src/sgml/refentry.sgml
deleted file mode 100644
index 64d102c130..0000000000
--- a/doc/src/sgml/refentry.sgml
+++ /dev/null
@@ -1 +0,0 @@
-<!doctype refentry PUBLIC "-//OASIS//DTD DocBook V3.1//EN">