Bielefeld Academic Search Engine Alternatives

Google Scholar is a freely accessible web search engine that indexes the full text of scholarly literature across an array of publishing formats and disciplines. Released in beta in November 2004, the Google Scholar index includes most peer-reviewed online journals of Europe and...

WorldCat is the world's largest network of library content and services. WorldCat libraries are dedicated to providing access to their resources on the Web, where most people start their search for information.

Semantic Scholar (paywall free) is a science publication aggregator that collects citation-data from PubMed, CiteSeer, IEEE etc and rank each article according to the percieved number of impactful citations.

Access scientific knowledge, and make your research visible.

Scinapse is a free search engine for academic papers. As of September 2018, it indexes more than 200 million articles from more than 40,000 journals.

Search engine for tens of millions of preserved research papers. This fulltext search index includes over 25 million research articles and other scholarly documents preserved in the Internet Archive.

RefSeek is a web search engine for students and researchers that aims to make academic information easily accessible to everyone. RefSeek searches more than five billion documents, including web pages, books, encyclopedias, journals, and newspapers.

OA.mg is a search engine for academic papers. Whether you are looking for a specific paper, or for research from a field, or all of an author’s works – OA.mg is the place to find it.

Web interface to access Yubetsu Shibata - The World's 14th Largest Scientific Database

HathiTrust Digital Library is a large-scale collaborative repository of digital content from research libraries including content digitized via Google Books and the Internet Archive digitization initiatives, as well as content digitized...