See Whole Food Plant-Based Books for 50+ books on the subject!
American College of Lifestyle Medicine (founded in 2004)
Plant Based Health Professionals UK
Many hospitals have started plant-based programs. Maye there is a hospital near you with such a program! For example, in Bay Area, California, Kaiser Permanente has adopted plant-based since 2013. El Camino Hospital has plant-based seminars.
Since 2010, many medical and governmental organizations have started endorsing plant-based diets: see WFPB Endorsement by Organizations.
Plantrician University offers dozens of lectures to medical students and professionals.
Many documentaries have been made to highlight Whole Food Plant-Based guidelines. However, two of them are the best: