Creative Commons

Creative Commons LicenseThis work by is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

You are free to use all the information and the material available on this site, in particular all the pictures presented here without further information about their source, under the following conditions:

Attribution: You have to refer to this site as the source.

Share Alike: You have to share all products which you have created using the material of this site under the same conditions.

Other sources used here

Quotations from literature are given in quotation marks and with reference to the source. All literature which has been used can be found in the bibliographies for the different languages: English, German, French, Russian.

If information has been taken from Wikipedia , the Wikipedia pages where the information has been taken from will be linked at the same page. Given that Wikipedia often changes, does not have a single author, particular information taken from Wikipedia is considered common knowledge and has not been marked otherwise.

If information has been taken from other websites, there will be more explicit references from the particular piece of information to the site where it has been taken from. But the problem that the content of the web changed appears here too. For example, the remarkable and highly recommended website has recently been redesigned. So, the original links to particular pages have become invalid and I had to remove them. Except for such situations, I give a link to the page where the information has been taken from on the same page where it has been used.

Please note also that, if you want to use the material found on this site using the Creative Commons license, you have to do it at your own risc. The author is not a lawyer and cannot give any warranties that the page does not contain any copyright violations against third parties. I think all what is done here does not violate any copyright and is in agreement with the general rules of fair use. But this is only my personal opinion.

Particular sources

The map has been used for the creation of some maps used on this site (this, this, and this).