Search by subject keywords or phrases. Online A selective academic search engine and index to online freely available scholarly articles, and journals. Results are listed by the user's choice of APA, MLA, or Chicago style. Directories classify Web resources by categories and subcategories. Some offer reviews or evaluations of sites.
Users can browse subjects or search by keyword.
Search a number of search engines at the same time and combine all the results in a single listing. Useful for very specific or obscure topics. The User's Guide to Web Searching - Compares and evaluates many different search engines.