Sooner or later, even the most expert searcher hits a wall using web search engines. There are many reasons for this, but the most common is that contrary to widely held myth, you can't find everything on the Internet.

If you ever find yourself stymied by a search engine, consider turning to a librarian for help. You don't even need to leave your computer to get assistance -- simply use one of the web's many "Ask a Librarian" (AskA) services.

You can even turn to the professionals at the world's largest library, the U.S. Library of Congress. The institution's AskA service is organized by topics, divided into general collections, international collections, and special formats and genres.

Click on a particular topic, and you're presented with a form to ask your question. Fill in the form, entering your question, name, email address, reason for research, education level and a few other bits of information.

The form also asks you to list the resources you've already consulted, a good idea for helping the librarians understand why you may not have come up with a satisfactory result.

Once you've submitted your question, a librarian will get back to you with an answer within 5 business days. This Ask a Librarian service uses QuestionPoint, a global, collaborative reference service run in conjunction with the Library of Congress, OCLC, and hundreds of participating libraries. In some cases, with your permission, the Library of Congress will forward your question to a librarian elsewhere who is participating in the QuestionPoint service.

For some topics, you can even chat with a librarian about your question. A small cartoonish dialog bubble next to a topic indicates that chat service is available during designated hours. The times for each topic are noted on the question form.

If a five day turnaround isn't quick enough, there are literally hundreds of other AskA services available on the web. Your local library may have an AskA service, possibly in conjunction with the QuestionPoint service mentioned above. Check your library's web site, or use the AskA+ Locator (link below) to locate a human search engine to help you find answers when you run into a dead-end with an online engine.

The Library of Congress: Ask a Librarian