Image: German1910

Description: German language around 1910. This image is unreferenced. The   dark cyan colour apparently denotes areas, where at least 50% of the population would speak German language. The inset claims it is from the "official national census of 1910", presumably the 1910 census in the German Empire. But it is not clear what relation this map is supposed to have to the census data, as most of its scope concerns territories which were not part of the German Empire. Presumably the "1910 census" claim is just pulled from thin air to avoid charges of "unreferenced". Until a decent reference is shown for this map, it should not be used in Wikipedia articles. Historical maps that could in principle be used as reference: (1881) , (1894), (1906), (1910). Here is a comparable map which claims it is derived from on "a map by Dr. V. Schmidt and Dr. J. Metelka". Presumably, this map is derived from a modern (recent) publication which discussed the 1910 census data. In this case, the map must be attributed to this publication, not to the "1910 census".
Title: German1910
Credit: Originally from en.wikipedia; description page is/was here.
Author: Original uploader and author was Rex Germanus at en.wikipedia
Permission: Rex Germanus at the English-language Wikipedia, the copyright holder of this work, hereby publishes it under the following license:
Usage Terms: Creative Commons Attribution-Share Alike 3.0
License: CC BY-SA 3.0
License Link: http://creativecommons.org/licenses/by-sa/3.0/
Attribution Required?: Yes