Description
Schmitt, M., The property identification of stamps by overprint or perforation, ca 2000, study on the vD overprints of the Dreyse needle gun factory in Sömmerda on NDP and breastplate stamps, which are considered to be the forerunners of the Perfins, as well as on the perforations of the other D. Reich issues up to Pfennige, 25 pages with illustrations; (good copies with ), #67943