1941 BANJA LUKA, One of the most rare FDC

The literature states that the philatelic club in Banja Luka issued only ten FDC envelopes, make this as one of the rarest FDC on the territory of the former Yugoslavia.

1941 Banja Luka, provisional issue, complete set on the Banja Luka philatelic club cover, cancelled 21.IV.41 - first day cover. Certificate Ercegović.