Nicaragua Scott #818a MNH S/S UNESCO HQ Opening $$
Nicaragua Scott #818a//C429a MNH S/S UNESCO HQ in Paris CV$5+
Nicaragua Scott #C429a MNH S/S UNESCO HQ in Paris MI BL#90 CV$4+
Nicaragua Scott #C503a MNH S/S UNESCO 25th ANN $$
Nicaragua Scott #C502-C503 MNH UNESCO 25th ANN $$