diff -r 0e40e05048eb -r 07444815c0bd plugins/redmine_bibliography/app/models/author.rb
--- a/plugins/redmine_bibliography/app/models/author.rb
+++ b/plugins/redmine_bibliography/app/models/author.rb
@@ -25,4 +25,13 @@
       self.authorships.first.institution
     end
   end
+
+  def mail
+    if self.authorships.first.nil?
+      ""
+    else
+      self.authorships.first.mail
+    end
+  end
+
 end