As a matter of habit and lack of information Google seems to be the only search engine on the internet, for anything. In fact, the "guru" of modern times. From the current to the unimaginable, it always seems to have a word to say, even if in half-truth, or simple speculation.

However, beyond this there are other unexplored options, mainly concerning literary and scientific works presented in books, articles and academic dissertations.

Walking around, we came across some options that can help you find even that very rare book you've been looking for so hard or had given up on... Just make sure those old books don't have the dust of time.... It's all digital.

Google is so powerful that it "hides" other search engines from us. We just don't know that most of them exist.

www.refseek.com - Academic Resources Search. More than a billion sources: encyclopedia, monographs, journals.

www.worldcat.org - a search for the contents of 20,000 libraries worldwide. Find out where the nearest rare book you need is located.

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

www.bioline.org.br is a library of scientific bioscience journals published in developing countries.

http://repec.org - Volunteers from 102 countries collected almost 4 million publications on economics and related sciences.

www.science.gov is an American state search engine on more than 2200 scientific sites. More than 200 million articles are indexed.

www.pdfdrive.com is the largest site for downloading free books in PDF format. Claiming more than 225 million names.

www.base-search.net is one of the most powerful text searches for academic studies. More than one hundred million scientific documents, 70% of them are free.