Bulgaria. (Prisoner of War Mail). 1918. Bulgarian postal stationery card 10b carmine written from Sofia dated '10th Mars 18' cancelled by 'Comite International de la Croix Rouge/ Geneva/ Agence des Prisonniers de Guerre' in red with hand-struck 'France de Port', addressed to France and forwarded to Switzerland and canceled by Geneva double ring '16th Mai' with Bulgarian military cachet and oval 'Ouvert/ Par L'Auorite Militaire/ 151' in blue on face. Attractive item.