Cleanup of the References section.

Removed non-functional links.
Removed links to API documentation.
Removed link to Rails 2 material.

Renamed "References" to "Further Reading".

railties/guides/source/caching_with_rails.textile

@@ -362,13 +362,9 @@ class ProductsController < ApplicationController
 end
 </ruby>
 
-h3. References
+h3. Further reading
 
 * "Scaling Rails Screencasts":http://railslab.newrelic.com/scaling-rails
-* "RailsEnvy, Rails Caching Tutorial, Part 1":http://www.railsenvy.com/2007/2/28/rails-caching-tutorial
-* "RailsEnvy, Rails Caching Tutorial, Part 2":http://www.railsenvy.com/2007/3/20/ruby-on-rails-caching-tutorial-part-2
-* "ActiveSupport::Cache documentation":http://api.rubyonrails.org/classes/ActiveSupport/Cache.html
-* "Rails 2.1 integrated caching tutorial":http://thewebfellas.com/blog/2008/6/9/rails-2-1-now-with-better-integrated-caching
 
 
 h3. Changelog