English: March Impromptu Code, the document alledgedly containing a code message from Martin Bormann to the leaders of the Nazi terror group Werwolven. This document was made available to the public for research purposes. The bottom of the image indicates the original score was from Collection Litolff No. 1189; this was published by Henry Litolff's verlag in Braunschweig, Germany in 1881 and credited to Josef Löw.[1][2] Löw's "Marsch Impromptu" may also have been published as part of Teacher and pupil : a practical course of four-hand piano playing by Schirmer in New York in 1893. News reports[3] however credit an 1876 work of the same name published in the U.S. by Gottlieb Federlein (1835 - 1922); however the Library of Congress deposit sample[4] does not seem to match. Gottfried Federlein (1883 - 1952) is sometimes credited, but appears to be Gottlieb's son and not related to the work in question. More discussion here.