Use SearchAll to search across all resources in the Library. Use the limit frature in the search results page to refine your search.
Use the Library databases to search for articles. Databases collect and index a big number of journals running through long time periods. Databases offer searching features that help you find what you need using and combining keywords, and limiting your search by type and date of publication. see Search Techniques.
Start your search using subject databases, then use Multidisciplinary databases for a broader coverage.