arXiv.org is an e-print service in the fields of physics, mathematics, non-linear science, computer science, quantitative biology, quantitative finance and statistics. It is owned, operated, and funded by Cornell University and partially funded by the National Science Foundation. Free resource.
IEEE Xplore Digital Library offers full-text access to many peer-reviewed IEEE magazines, journals (in some cases, including preprints) and more than 1500 conference publications and proceedings. Documents are available in HTML and PDF formats. Content ranges from the 1970s to the present, depending on the publication.
ProQuest Psychology Journals indexes 300 academic journals in psychology and related fields. Updated daily.
PsycARTICLES contains full-text, peer-reviewed scholarly and scientific articles from journals published by the American Psychological Association, the APA Educational Publishing Foundation, the Canadian Psychological Association, and Hogrefe & Huber.
ScienceDirect (Elsevier) offers full-text journal articles from more than 450 peer-reviewed journals in arts and humanities, business, management, accounting, decision sciences, economics, econometrics, finance, psychology, and social sciences.