diff --git a/lib/eeepub/maker.rb b/lib/eeepub/maker.rb
index bae94a1..84fc878 100644
--- a/lib/eeepub/maker.rb
+++ b/lib/eeepub/maker.rb
@@ -54,6 +54,7 @@ def #{name}(value)
       :files,
       :nav,
       :cover,
+      :source,
       :ncx_file,
       :opf_file,
       :guide
@@ -133,6 +134,7 @@ def create_epub
         :description => @descriptions,
         :rights => @rightss,
         :cover => @cover,
+        :source => @source,
         :relation => @relations,
         :manifest => @files.map{|file|
           case file
diff --git a/lib/eeepub/opf.rb b/lib/eeepub/opf.rb
index 237ad45..3798643 100644
--- a/lib/eeepub/opf.rb
+++ b/lib/eeepub/opf.rb
@@ -15,6 +15,7 @@ class OPF < ContainerItem
                   :spine,
                   :guide,
                   :cover,
+                  :source,
                   :ncx,
                   :toc
 
@@ -71,7 +72,7 @@ def build_metadata(builder)
           builder.dc :identifier, i[:value], attrs
         end
 
-        [:title, :language, :subject, :description, :relation, :creator, :publisher, :date, :rights].each do |i|
+        [:title, :language, :subject, :description, :relation, :creator, :publisher, :date, :rights, :source].each do |i|
           value = self.send(i)
           next unless value
 
diff --git a/spec/eeepub/maker_spec.rb b/spec/eeepub/maker_spec.rb
index bd5b1d6..993b3d1 100644
--- a/spec/eeepub/maker_spec.rb
+++ b/spec/eeepub/maker_spec.rb
@@ -17,6 +17,7 @@
       ncx_file 'toc.ncx'
       opf_file 'content.opf'
       cover 'cover.jpg'
+      source 'http://example.com/book/foo'
       files ['foo.html', 'bar.html']
       nav [
         {:label => '1. foo', :content => 'foo.html'},
@@ -34,6 +35,7 @@
   it { @maker.instance_variable_get(:@ncx_file).should == 'toc.ncx' }
   it { @maker.instance_variable_get(:@opf_file).should == 'content.opf' }
   it { @maker.instance_variable_get(:@cover).should == 'cover.jpg' }
+  it { @maker.instance_variable_get(:@source).should == 'http://example.com/book/foo' }
   it { @maker.instance_variable_get(:@files).should == ['foo.html', 'bar.html'] }
   it { 
     @maker.instance_variable_get(:@nav).should == [
@@ -54,20 +56,22 @@
       :uid=>{:value=>"http://example.com/book/foo", :scheme=>"URL", :id=>"http://example.com/book/foo"}
     ) { stub!.save }
     mock(EeePub::OPF).new(
-      :title => ["sample"],
-      :creator => ["jugyo"],
-      :date => ["2010-05-06"],
-      :language => ['en'],
-      :subject => ['epub sample'],
-      :description => ['this is epub sample'],
-      :rights => ['xxx'],
-      :relation => ['xxx'],
-      :ncx => "toc.ncx",
-      :cover => 'cover.jpg',
-      :publisher => ["jugyo.org"],
+      :title=>["sample"],
       :unique_identifier=>"http://example.com/book/foo",
-      :identifier => [{:value => "http://example.com/book/foo", :scheme => "URL", :id => "http://example.com/book/foo"}],
-      :manifest => ['foo.html', 'bar.html']
+      :identifier=>[{:value=>"http://example.com/book/foo",:scheme=>"URL", :id=>"http://example.com/book/foo"}],
+      :creator=>["jugyo"],
+      :publisher=>["jugyo.org"],
+      :date=>["2010-05-06"],
+      :language=>["en"],
+      :subject=>["epub sample"],
+      :description=>["this is epub sample"],
+      :rights=>["xxx"],
+      :cover=>"cover.jpg",
+      :source=>"http://example.com/book/foo",
+      :relation=>["xxx"],
+      :manifest=>["foo.html", "bar.html"],
+      :ncx=>"toc.ncx",
+      :guide=>nil
     ) { stub!.save }
     mock(EeePub::OCF).new(
       :container => "content.opf",
@@ -94,6 +98,7 @@
         ncx_file 'toc.ncx'
         opf_file 'content.opf'
         cover 'cover.jpg'
+        source 'http://example.com/book/foo'
         files [{'foo.html' => 'foo/bar'}, {'bar.html' => 'foo/bar/baz'}]
         nav [
           {:label => '1. foo', :content => 'foo.html'},
@@ -108,20 +113,22 @@
       mock(Dir).mktmpdir { '/tmp' }
       mock(EeePub::NCX).new.with_any_args { stub!.save }
       mock(EeePub::OPF).new(
-        :title => ["sample"],
-        :creator => ["jugyo"],
-        :date => ["2010-05-06"],
-        :language => ['en'],
-        :subject => ['epub sample'],
-        :description => ['this is epub sample'],
-        :rights => ['xxx'],
-        :relation => ['xxx'],
-        :ncx => "toc.ncx",
-        :cover => 'cover.jpg',
-        :publisher => ["jugyo.org"],
-        :unique_identifier=>"http://example.com/book/foo",
-        :identifier => [{:value => "http://example.com/book/foo", :scheme => "URL", :id=>"http://example.com/book/foo"}],
-        :manifest => ["foo/bar/foo.html", "foo/bar/baz/bar.html"]
+          :title=>["sample"],
+          :unique_identifier=>"http://example.com/book/foo",
+          :identifier=>[{:value=>"http://example.com/book/foo", :scheme=>"URL", :id=>"http://example.com/book/foo"}],
+          :creator=>["jugyo"],
+          :publisher=>["jugyo.org"],
+          :date=>["2010-05-06"],
+          :language=>["en"],
+          :subject=>["epub sample"],
+          :description=>["this is epub sample"],
+          :rights=>["xxx"],
+          :cover=>"cover.jpg",
+          :source=>"http://example.com/book/foo",
+          :relation=>["xxx"],
+          :manifest=>["foo/bar/foo.html", "foo/bar/baz/bar.html"],
+          :ncx=>"toc.ncx",
+          :guide=>nil
       ) { stub!.save }
       mock(EeePub::OCF).new.with_any_args { stub!.save }
 
diff --git a/spec/eeepub/opf_spec.rb b/spec/eeepub/opf_spec.rb
index db4d580..11b7ba7 100644
--- a/spec/eeepub/opf_spec.rb
+++ b/spec/eeepub/opf_spec.rb
@@ -119,7 +119,8 @@
         :creator => 'creator',
         :publisher => 'publisher',
         :rights => 'rights',
-        :cover => 'cover.jpg'
+        :cover => 'cover.jpg',
+        :source => 'source'
       )
     end
 
@@ -136,6 +137,7 @@
         ['dc:relation', 'relation'],
         ['dc:creator', 'creator'],
         ['dc:publisher', 'publisher'],
+        ['dc:source', 'source'],
         ['dc:rights', 'rights'],
       ].each do |xpath, expect|
         metadata.xpath(xpath,