rails many to many self join

Question

could some one point me to the right direction:

I try to build a model for rails that build up the following:

ClassA -id

ClassA has a relation to

Answer 1

This post has a good working example: http://blog.hasmanythrough.com/2007/10/30/self-referential-has-many-through

There is a related question here as well: Problem with self-referential has_many :through associations in Rails