The Max Planck Society has signed an agreement with Elsevier for a new ebooks model. During an initial period of 12 months, almost 13.000 ebooks from more than 20 subject areas will be accessible (book series are not included).
At the end of this initial period, a number of ebooks will be selected for perpetual access, primarily based on usage in the previous months.

The ebooks are available at http://www.sciencedirect.com