If you don t find what you want, modify your search strategy. If you re still not satisfied, try another search engine or subject directory. Remember, too, that not everything is available on the Internet. Librarians are experienced Internet searchers and can advise you in your searching. This is one of the most common mistakes.
Spaces are also important.
Searching for wavelength and wave length will retrieve different results. Be specific and use more than one word. Some search engines automatically use truncation. Boolean operators are the words AND , OR , and NOT and they are used to link search concepts. Some databases will automatically insert AND or OR between each of your search terms.