According to the primary Math-Net site
http://www.math-net.de/
the Math-Net is since July 2007 out of order.

The MathNet.preprints are
still available, the same applies to the **Technical reports
at the Faculty of Mathematics and Computer Science
(Friedrich-Schiller-Universität Jena)**.

You may want to look at the directory of
preprints of the Faculty of Mathematics and Computer Science.

Last Change: 2013-02-28