In: Homepage des Instituts für Geschichte der Universität Hildesheim http://www.uni-hildesheim.de/media/geschichte/Geschichte Ultraimperialismustheorie.pdf (available since January 20, 2008).
The provided URL leads to a webpage containing a document titled "Ultraimperialism Theory" from the Institute for History at the University of Hildesheim, which is publicly accessible since January 20, 2008.