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 sites you never heard of.

www.refseek.com (http://www.refseek.com/) - Academic Resource Search. More than a billion sources: encyclopedia, monographies, magazines.

www.worldcat.org (http://www.worldcat.org/) - a search for the contents of 20 thousand worldwide libraries. Find out where lies the nearest rare book you need.

https://link.springer.com (https://link.springer.com/) - access to more than 10 million scientific documents: books, articles, research protocols.

www.bioline.org.br (http://www.bioline.org.br/) is a library of scientific bioscience journals published in developing countries.

http://repec.org (http://repec.org/) - volunteers from 102 countries have collected almost 4 million publications on economics and related science.

www.science.gov (http://www.science.gov/) is an American state search engine on 2200+ scientific sites. More than 200 million articles are indexed.

www.base-search.net (http://www.base-search.net/) is one of the most powerful researches on academic studies texts. More than 100 million scientific documents, 70% of them are free.