ScienceDirect is a searchable web-based bibliographic database, which provides access to full texts of scientific and medical publications of the Dutch publisher Elsevier as well of several small academic publishers. It hosts over 18 million publications from more than 4,000 academic journals and 30,000 e-books. The access to the full-text requires subscription, while the bibliographic metadata are free to read. ScienceDirect was launched by Elsevier in March 1997.