Espanha – 1931 – STW-30-35 – Airmail – The 3rd pan american postal congress (selos oficiais)

STW-30 – 5c – castanho amarelado
STW-31 – 10c – verde
STW-32 – 25c – roseta
STW-33 – 50c – azul claro
STW-34 – 1pta – roxo
STW-35 – 4pta – cinzento