ProQuest databases include full-text scholarly journals, as well as other source types, in all subject areas. Check the Peer Reviewed box to limit your search results to scholarly journals, and then in the search results, filter by Document Type to limit results to Articles (this will remove editorials, letters, book reviews, and other non-reviewed items from the results).
JSTOR Open Access Content provides free access to thousands of ebooks and hundreds of academic journals. Create your own free profile to read articles online.