Draft article

what is

GoF Delegation

<a href="http://www.saturnflyer.com/blog/jim/2012/07/06/the-gang-of-four-is-wrong-and-you-dont-understand-delegation/">The Gang of Four is wrong and you don't understand delegation - Saturn Flyer with Jim Gay</a>www.saturnflyer.com

non-free article

Using prototypical objects to implement shared behavior in object-oriented systems

free article

http://web.media.mit.edu/~lieber/Lieberary/OOP/Delegation/Delegation.html

SO answer

<a href="http://stackoverflow.com/a/2044357">What is Delegate?</a>stackoverflow.com

etc

<a href="http://blog.jnito.com/entry/20110706/1309901221">デリゲート(delegate)ってなんだろう？ - give IT a try</a>blog.jnito.com

when to use

<a href="http://blog.shinetech.com/2011/06/14/delegation-notification-and-observation/">When to use Delegation, Notification, or Observation in iOS</a>blog.shinetech.com