"PubMed Central® (PMC) is a free full-text archive of biomedical and life sciences journal literature at the U.S. National Institutes of Health's National Library of Medicine (NIH/NLM)."
"FoodData Central is an integrated data system that provides expanded nutrient profile data and links to related agricultural and experimental research."
"Medrxiv is an Internet site distributing unpublished manuscripts about health sciences. It distributes complete, but unpublished manuscripts in the areas of medicine, clinical research, and related health sciences without charge to the reader." (Wikipedia)
PLOS is a nonprofit, Open Access publisher empowering researchers to accelerate progress in science and medicine by leading a transformation in research communication.
"You can search the database by food item, food group, or manufacturer's name to find the nutrient information for your food items. You can also generate lists of foods sorted by nutrient content."
Explain that Stuff is an online book written by science writer Chris Woodford. It includes over 400 easy-to-understand articles, richly illustrated with over 4000 photos, artworks, and animations, covering how things work, cutting-edge science, cool gadgets, and computers.
NoodleTools is an online research management platform that helps you evaluate information, build accurate citations, archive source material, take notes, outline topics, and prepare to write. Sign in with Google.
"Google Scholar is a freely accessible web search engine that indexes the full text or metadata of scholarly literature across an array of publishing formats and disciplines."
"ResearchGate is a European commercial social networking site for scientists and researchers to share papers, ask and answer questions, and find collaborators." Many studies are available free by contacting the authors through ResearchGate.
This "database contains over 16 500 peer-reviewed open access journals covering all areas of science, technology, medicine, social sciences, arts and humanities."