Try these first:
Open Access materials can be excellent resources to supplement online library materials. Many scholarly and peer-review journals have opened their back issues as open access, and others have converted partially or totally to open access for all issues. The following are listing of open access resources that could assist in your research :
American Mathematical Society
AMS peer-reviewed journals are of the highest quality in mathematical research. Our journals have been published since 1891 and cover a broad range of mathematics. Each journal is managed by editors who are prominent in their fields, and each is unique in its offering of articles, book reviews, and reports.
Open access pre-prints in physics, mathematics, computer science, quantitative biology, quantitative finance and statistics.