"Jugend: Münchner illustrierte Wochenschrift für Kunst und Leben"
München u. Leipzig 1896-1925
I found this magazine on-line. It's a pretty good source of beautiful period popular graphic artwork. For the military buffs many issues have full page artwork of German troops. For the costume buff there are lots of fashion images. I'm having trouble translating some captions as they are in German script. Years 1914-1918 are particularly good for war art and propaganda. Click on the year, then click on the picture on the right of the screen that appears and thumbnails of all the issues and pages for half the year will appear. These are enlargeable and down loadable.
Here are some examples....
Another 1914 image.