The "Beach Ball" Analogy

My husband has an explosive anger issue that often catches us both off guard. When I explained Brooke’s analogy comparing suppressing emotion to trying to hold a beach ball under water until it eventually pops up to the surface, it really resonated with him. He’s like to read more about it, but I can’t remember where I read it in the materials. Can someone point me in the right direction? I’ve saved everything.