NCBI Bookshelf is a free collection of more than 9000 books, reports, databases, and other pieces of peer-reviewed scholarship in the areas of biology, medicine, and the life sciences. It is developed and managed by the National Center for Biotechnology Information (NCBI) at the National Library of Medicine. Content in NCBI Bookshelf is made available by participating authors, editors, funders, sponsors, and publishers. National Library of Medicine evaluates each publication to ensure its meets scientific and technical standards. NCBI Bookshelf includes links integrating its content with other NCBI databases.
Varies per publication.
National Center for Biotechnology Information (NCBI)