Pediatrician Says We Need Specialist

Our pediatrician basically told us at the last checkup that she's done all she can and we need to see a child psychiatrist for our 9 year old. He's been having these intense meltdowns that are way beyond normal tantrums and she thinks there might be something more going on. Problem is I have no idea how to even find a good one or what to look for. Do you have any recommendations for someone who works with kids his age? I'm feeling pretty overwhelmed and just want to make sure we get him to the right person.