In the following some completing and additional remarks will be given.

I think that it became obvious that English is not my native language. Please, let me know your suggestions and inform me about appropriate changes and necessary corrections of the text.

One of the essential guidelines for the preparation of the homepage is to restrict myself to simple features of HTML. The main reason for that is to assure an identical presentation of the pages for different browsers as far as possible. This is not true for the presentations of banknote with the portrait of C. F. Gauß und banknote with the portrait of L. Euler (virtual exposition "Monuments on Mathematicians") where the script language JavaScript is applied too.

During the phase of preparing the internet pages their presentation has been tested with the version 3.02a.2916 and 4.0.1812 of the Microsoft Internet Explorer as well as version 4.04 of the Netscape Navigator. Certainly changes and new pages are checked with newer versions of these browsers. Actually Microsoft Internet Explorer version 5.5 and Netscape Navigator Version 4.7 are used.

After publishing the pages in the internet, a conformity check has been carried out by means of the W3C HTML Validation Service, which is provided by W3-consortium. This check will be repeated but not periodically. The last one was performed in January 2003. Following deviations with respect to the HTML-Standard have been reported:

• The references to the entries of the Zentralblatt für Mathematik in the list of the publications contain the character "&", which possesses a special meaning in HTML.
• For the code inserted below on this page concerning the dialog box contains a deviation from the standard is reported. The same occurs for the same page in german.
• For the automatically generated code for presenting the integral equation several errors are reported.

This means that except of the pages mentioned all pages completely satisfy the HTML-standards. This justifies the placement of the label here on the right.

Informations how to prepare browser-independent HTML-documents are available under http://www.anybrowser.org/campaign.

There is also another service for checking web pages, which can be used directly with the following form.