Printed 'Secretaria de la Economia Nacional - Oficina de Publicaciones' OFFICIAL postcard franked with 2 x 1933 3c brown 'SERVICIO OFICIAL' overprint issue (SG O542) tied by OFICIAL MEXICO D.F. cds dated 19 JUL 1934. Addressed to the UNITED NATIONS in GENEVE, SWITZERLAND, the message being an acknowledgment for receipt of the latest UN publication 'Differend entre la Bolivie et le Paraguay - Rapport de la commission du Chaco' dealing with the Chaco War between Bolivia & Paraguay.