Scholarly journal articles with a heavy emphasis on science. International scope. Excellent for citation searching. 1996-present for citation searching; 1966 to present for general searching.
Access: Off Campus Access is available for: UNC-Chapel Hill students, faculty, and staff; UNC Hospitals employees; UNC-Chapel Hill affiliated AHEC users.
Search Google Scholar for the journal PLos One. You'll see that multiple articles in this journal have been been cited hundreds of times, lending the open access title lots of credibility.