Julian, Secret Agent by Ann Cameron

Julian to the rescue!Grown-ups aren't very good at solving crimes. That's why it's time for Julian, Huey and Gloria to take matters into their own hands. The crime-busting kids go on a mission to track down wanted criminals. They have a special motto, a secret code and plenty of plans. All they need now is their first crook . . .
Binding: Paperback / softback