Lower case words will search for both lower and upper cases. Use special keywords like anchor, applet, host, url etc. Always use the advanced search made available by the search engine. Read up the help section provided there on how to use the advanced search. When a search does not yield the desired result, most of the time people try with a modified input on the same search engine rather than searching the same word or phrase on a different engine, the apparent assumption being that all search engines are the same.
Nothing is farther from truth.
You need to be discerning and discriminating. All engines are not the same. The way the engines rank their findings in terms of relevance is often irrational. Moreover, there are the manipulations by eager webmasters to put their site on the top. For example, you often come across sites that have nothing to do with the subject under search, but have been catapaulted to the top.