Use Google Scholar to find articles from a wide variety of academic publishers, professional societies, preprint repositories and universities, as well as scholarly articles available across the Web. A drawback is that not all articles are free.
Academic Search Complete is the world's most valuable and comprehensive scholarly, multi-disciplinary full-text database, with more than 8,500 full-text periodicals, including more than 7,300 peer-reviewed journals.
In addition to full text, this database offers indexing and abstracts for more than 12,500 journals and a total of more than 13,200 publications including monographs, reports, conference proceedings, etc. The database features PDF content going back as far as 1887, with the majority of full text titles in native (searchable) PDF format. Searchable cited references are provided for more than 1,400 journals.
Political Science Database gives users access to hundreds of leading political science, public policy, and international relations journals. It also includes thousands of recent full-text doctoral dissertations on political science topics, together with working papers, conference proceedings, country reports, policy papers and other sources.