Searching "vegan", "vegetarian" and "plant-based" on Google Scholar shows over a million results.
You can find many studies related to Whole-Food Plant-Based diets presented in a more accessible manner in Dr. Michael Greger's excellent Nutrition Facts website. All videos have a "Sources Cited" tab with links to all the references.
For veganism in general, not just health and diet, I don't know any good source, but on YouTube there's Mic the Vegan, who is always talking about new studies, documentaries, and news articles related to veganism. He usually gives very accurate and accessible summaries even though he's not a doctor or scientist.