Google Books (previously known as Google Book Search, Google Print, and by its code-name Project Ocean) is a service from Google Inc. that searches the full text of books and magazines that Google has scanned, converted to text using optical character recognition (OCR), and stored in its digital database. Books are provided either by publishers and authors through the Google Books Partner Program, or by Google's library partners through the Library Project. Additionally, Google has partnered with a number of magazine publishers to digitize their archives. More information...
According to PR-model, books.google.com is ranked 3rd in multilingual Wikipedia, in particular this website is ranked 3rd in English Wikipedia.
The website is placed before nih.gov and after doi.org in the BestRef global ranking of the most important sources of Wikipedia.