Google Scholar
Google search engine devoted to academic and scientific documents.
Google search engine applied exclusively to documents from the academic and scientific world. It includes all kinds of disciplines and sources: articles, theses, books, reviews and even patents, from the websites of academic publishers, professional societies, scientific repositories and universities, a large part of them in full text or with links to the text. Not only does it allow to search among more than 200 M indexed documents, but, when possible, it offers a fragment of the abstract, citations, other related articles and the impact of the document through citations. The advanced search option allows to specify the search strategy. With a Google account any use can create a personal Library with a selection and set alerts. It also allows exporting the reference to different styles of bibliographic citation.