The Austro-German Postal Union of 1850
Deutsche Hufeisenstempel (in German)
Emergency Posting Measures from 1945
Feldpost 1939-1945 (in German)
German Private Posts (RPSL)
Inter-Camp Polish Post in Germany in 1945
Oberpostdirektion: Postal history of the Emergency Stamps of Sept. to Dec. 1923
Postal History of Sonthofen (Bavaria)
Sudetenland 1938-1945
Discussion Group: Allied Occupation of Germany after WWII, Stamps and Postal History
Discussion Group: Third Reich Stamps and Postal History
Study Group of the Collectors of German Colonial Stamps
Germany Philatelic Society (US)
Germany & Colonies Philatelic Society (UK)
INFLA - Berlin (German Inflation Period)
Briefmarke.com
Christ Stamps
Ulrich Felzmann Auction
Philatelie-Gärtner
Gothic Stamps
Haus der Briefmarke
HBA Auctions
Hobbyphilatelie Höflich KG
Interphila Grobe und Lange Auction
Just Prephilately
Albert Kiel - Briefmarken
Heinrich Köhler Auction
Edgar Mohrmann & Co
Nahues Auction
Till Neumann - Klassische Philatelie
Phila-Studio
Potsdamer Philatelistisches Büro Auction
Peter Richardson
R. Schneider Stamps
Schnellbacher Philately
Schwanke & Sohn Hamburg (Auctions)
Lenz Singen Briefmarken
Bade, Henri. 333 Years of Brunswick Postal History and Stamps [333 Jahre Braunschweigische Post], 1960; (in German).
Drechsel, Edwin. 1886-1986: A Century of German Ship Posts, 1987.
Feuser, Peter and Münzberg, Werner German Stampless Markings, [Deutsche Vorphilatelie], date?
Feuser, Peter and Münzberg, Werner, German Transit Markings, 1991.
Gibbs, Robert M. The Postage Stamps of the German Colonies occupied by the British, 1914-1918 [New Guinea and the Marshall Islands,
Cameroons, Mafia, Samoa, Togoland], 1988.
Gottspenn, Arno. German Seepost Cancellations 1886-1939. Part 1, European, North & South Atlantic Routes, 1986, Cockrill
Booklet 46; Part 2, African, Asian & Australasian Routes, 1987, Cockrill Booklet 47.
Manchester, Diana. Postal Rates of Germany 1906 -1923, 1991.
Munk, Herbert. Kohl-Briefmarken Handbuch, Vol 1 - 4, 1926-1933, (in German).
Pennycuick, K. The Postal History of German East Africa, edited by Edward B. Proud 1989.
Schwab, Henry. The Echoes That Remain, [The philatelic story of the Nazi Persecution and the Holocaust], 1992.
Stich Dr. H.F. and W. Postwar Years of Germany 1945-48, 1994.