Safe Flow - Provides backflow prevention training to professionals in the plumbing, pipefitting, fire suppression, irrigation and service industries. Based in Columbia, Missouri. - http://www.safeflow.com/
Watts Backflow Directory - Online directory of certified backflow testers and training schools in Canada. - http://www.backflow.ca/
Kansas City Backflow - ASSE certified school for backflow tester certification and re-certification. Offers regularly scheduled training classes and testing in Kansas City, Missouri. - http://www.kcbackflow.com/
Water Specialties Company - Backflow preventer sales and parts supplier. - http://www.backflowpreventer.com/