What's good reading for Phalcon when on a trip?

I'm going to be spending a lot of time on a plane. I'll be using a Kindle for reading.

Other than the Getting Started with Phalcon book and downloading the documentaion off the site, what are other good resources to get?

edited Dec '14

If you are motivated to use Phalcon so my proposition for you is to learn Zephir language as well. It takes sth about 2 hours. You can grasp some general knowledge about PHP or programming or even managment.

PHP: unit testing, phpDoc, codeception, version control, security concerns e.g. OWASP pages.

Programming: "Patterns of Enterprise Application Architecture" by Martin Fowler

Scrum agile: "Essential Scrum A Practical Guide to the Most Popular Agile Process" by Kenneth S. Rubin