These are grouped into 21 categories. Employment links to fifty sites to search for jobs. The My Search Engines part of My Reference Desk links to 260 specialized search engines. My Search Engines groups these databases into categories like a subject tree. A subject tree links to web pages on a subject.
Users go to the database and search the database.
To select more than one engine or tree in the window, hold down the key and click on the engines or trees to search. To search the other databases click on the categories on the left side of the page. Filters results to remove duplicates and broken links. The m and broken links. A subject tree links to web pages on a subject.