calibre - Ebook manager, viewer & converter
Google Scholar - Google Scholar is a freely accessible web search engine that indexes the full text of scholarly...
Apple Books - The all-new Apple Books has been redesigned to make finding, reading, and listening to books a beautiful, effortless experience on iPhone and iPad.
Scinapse - Scinapse is a free, nonprofit, Academic search engine for papers, serviced by Pluto Network.
Open Library - The ultimate goal of the Open Library is to make all the published works of humankind available to...
Scopus - Scopus is a bibliographic database containing abstracts and citations for academic journal articles.