User blog comment:Redgarlic68/‘Phineas And Ferb’ Creators Sign Deals With Disney For Series, Feature, Potential Spinoff/@comment-5151799-20110826005342

If anyone needs a source, here's one: http://www.cinemablend.com/television/Phineas-Ferb-Creators-Earn-Contract-With-Disney-Plan-Two-Series-34557.html