BELGIAN EXPEDITIONARY CORPS OF ARMORED CARS IN RUSSIA: 1915, German occupation postal stationary card 5 c. with additional franking with full text on front and reverse from members of his family to Theo Halleux, a well-known member of the corps, first to a undercover address in the Hague, here newly franked with a Dutch stamp and sent to St. Petersburg with arrival mark "PETROGRAD OTD. DOST. VYSOCH. KOR. 8-10.15"; a scarce and interesting card of WW I postal history