Ruby Snack #11: Nested Forms Part 4: Has Many Through
У вашего броузера проблема в совместимости с HTML5
Wrapping up this series on Nested Forms, we'll add another section to our form in order to create a has many through association.
You can download the pdf of the presentation here: http://rubythursday.com/episodes/ruby-snack-11-nested-forms-has-many-through