Springer Science+Business Media or Springer is a global publishing company that publishes books, e-books and peer-reviewed journals in science, technical and medical (STM) publishing. Springer also hosts a number of scientific databases, including SpringerLink, Springer Protocols, and SpringerImages. Book publications include major reference works, textbooks, monographs and book series; more than 168,000 titles are available as e-books in 24 subject collections. Springer has major offices in Berlin, Heidelberg, Dordrecht, and New York City. On January 15, 2015, Georg von Holtzbrinck Publishing Group / Nature Publishing Group and Springer Science+Business Media announced a merger.