Dogpile Savvy Search MetaCrawler WWW Search Engines collect web pages in searchable databases. Tile.net Simultaneously searches mailing lists, usenet newsgroups and FTP sites Directories only include sites selected by professionals for the quality of their content.
Directories are often more effective than search engines in locating research-level web sites.
Argus Clearinghouse Highly selective searchable database of academically oriented web sites. Few sites but high quality. Simultaneously searches Encyclopedia Britannica, EB's database of selected sites, magazine articles and related books. BUBL LINK Like Argus Clearinghouse but more sites and more complete list of subjects. Internet Public Library Virtual books, magazines and newspapers.