Home / Stamps / AUSTRALIA / POSTAL HISTORY / SIGMA FIRST DAY COVERS / AUSTRALIA – 1973 ‘WORLD HEALTH ORGANISATION’ Sigma First Day Cover [B5414] AUSTRALIA – 1973 ‘WORLD HEALTH ORGANISATION’ Sigma First Day Cover [B5414]Description Fine Condition. Price(AUST) $10.00 1 in stock Buy with – OR – Add to cart SKU: B5414 Categories: AUSTRALIA, FDCs - DECIMAL, POSTAL HISTORY, SIGMA FIRST DAY COVERS, Stamps