On Tuesday, September 15, 2009 at 2 p.m., Heinrich Koehler auctions https://www.heinrich-koehler.de/de/news/ from Wiesbaden, Germany auctions some very nice zeppelin- and airmail covers.
The ZEPPELIN STUDY GROUP http://www.ezep.de/index.html is meeting after the Heinrich Koehler zeppelin mail auction at Wiesbaden. The meeting is open to the public, registration is not required.
Link of the zeppelin mail auction: https://www.heinrich-koehler.de/de/auction/337/g_1_10/