http://www.slideshare.net/abdels/my-adventuresinobjc http://blog.phusion.nl/2010/03/24/objective-c-for-ruby-developers-un-not-so-petit-interlude-1/ http://paulsturgess.co.uk/blog/2013/04/25/objective-c-for-a-rubyist/ https://speakerdeck.com/eddie/my-way-to-objective-c