I've been reading Champlain's Dream (not a novel, I know), by David Hackett Fischer, and was curious about a colorful character known as "Captain Provençal"; Champlain's swashbuckling uncle. I typed the name into the Google search box but was disappointed to get only two relevant hits. I looked again at the search box; oops, I had typed "captain provancal". Correcting my spelling yielded much better results. Even the misspelling, however, led me to Champlain's Dream in Google Books. I decided to do some search engine testing there, since I already knew that the Captain was mentioned many times.
In case you haven't used it, Google Books has a great search feature that will search within a book and show snippet views of passages containing your search terms. I was puzzled, though. A search usually highlights instances of the search words. My search showed only a page of the book, without any highlighted words. That was when I discovered my spelling error. Correcting the spelling improved my results in the regular Google Search, but still no highlights appeared in the Google Books text search results. Maybe capitalization is important? I tried searching on "Captain Provencal" - still no highlights. It was only when I replaced the regular "c" with the French "ç" that the search found and highlighted the name "Captain Provençal" inside Champlain's Dream. It seems that the search engine inside Google Books is much less "fuzzy" than regular Google Search. So, to find exactly what you're searching for, don't forget those diacritical marks.