access 160+ million publications and connect with 25+ million researchers. join for free and gain visibility by uploading your research.

open library is an open, editable library catalog, building towards a web page for every book ever published. read, borrow, and discover more than 3m books for free.

yumpu releases magazines, documents and catalogs on the internet. publish for free. gain new readers and costumers worldwide.

library genesis is a scientific community targeting collection of books on natural science disciplines and engineering.

academia.edu is a place to share and follow research.

save up to 90% on textbooks. read over a million professional and academic ebooks in one simple space.

semantic scholar uses groundbreaking ai and engineering to understand the semantics of scientific literature to help scholars discover relevant research.

find and read more books you’ll love, and keep track of the books you want to read. be part of the world’s largest community of book lovers on goodreads.

you may publish any number of documents in pdf, microsoft word and powerpoint format. all files uploaded to the website are automatically adapted for displaying on ipad, iphone, android and other platforms.

mdpi is a publisher of peer-reviewed, open access journals since its establishment in 1996.