First, no search engine covers anything close to the entire, so it's best to use more than one. Expert searches suggest that you use at least four. Second, search engines only give a past picture of the Web. This may be recent or not so recent, but this means there's a chance that some of the links pulled up by a search engine don't exist anymore. Third, search engines can't judge the quality of information provided by a web site.
Results can be pure platinum or utter twaddle.
Tips for using Search Engines Be specific as possible. Think about the concepts behind your search. If your search isn't coming up with anything try using other terms that might describe what you're looking for. When all else fails, read the help section. Web Subject Directories.