Bulgaria 1987 Space Research perf m/sheet, SG MS 3472, Mi BL 174A (with corrected inscription) unmounted mint
Bulgaria 1987 Space Research perf m/sheet, SG MS 3472, Mi BL 174A (with corrected inscription) unmounted mint
Bulgaria 1987 Space Research perf m/sheet, SG MS 3472, Mi BL 174A (with corrected inscription) unmounted mint