Google is so powerful that it "hides" other search systems from us. We just don't know the existence of most of them.
Meanwhile, there are still a huge number of excellent searchers in the world who specialize in books, science, other smart information.
Keep a list of these sites for reference:
BASE (Bielefeld Academic Search Engine): Basic Search
More than 400 mio. scientific documents from more than 11.000 content providers. BASE is one of the world's most voluminous search engines for academic web resources.
(base-search.net)