When searching for journal articles, a database is usually the best place to begin. Databases collect articles from a large number of journals in one place.
Worldwide Political Science Abstracts (ProQuest)
Worldwide Political Science Abstracts provides "citations, abstracts, and indexing of the international serials literature in political science and its complementary fields, including international relations, law, and public administration / policy."
Public Affairs Information Service (PAIS) International and Archive (ProQuest)
The PAIS International database contains references to journal articles, books, government documents, statistical directories, grey literature, research reports, conference reports, publications of international agencies, microfiche, Internet material, and more. Newspapers and newsletters are not indexed. Also included in PAIS are the PAIS Archive and ProQuest Deep Indexing: Public Administration and Policy databases.
ProQuest political science
ProQuest Political Science gives users access to hundreds of leading political science and international relations journals, providing full-text of many core titles indexed in Worldwide Political Science Abstracts. In addition, over a thousand recent full-text doctoral dissertations on political science topics are included, together with working papers, conference proceedings, country profiles, political news and other sources.
ProQuest Political Science covers the literature of political science and international relations, including such topics as comparative politics, political economy, international development, environmental policy, and hundreds of related topics.
Scopus, a multidisciplinary online resource, will be invaluable to students and faculty in various fields of study within the sciences, health sciences and the social sciences. Scopus offers full-text linking, abstracting-and-indexing information including peer-reviewed titles from international publishers, Open Access journals, conference proceedings, trade publications, quality web sources.
Google Scholar searches a subset of the Web that Google has classified as "scholarly literature". They do not publish a list of chosen sites, and they do not state how often sites are checked. Some important sources are not covered at all. Thus, Google Scholar alone should not be relied on for comprehensive research.