Abartenführer : Anleitung zur Bestimmung von Abarten, Abweichungen und Fehlern auf Briefmarken. 0000
Billig's Philatelic Handbook, vol. 34, The Encyclopaedia of British Empire Postage Stamps 1661 - 1951, Vol. 1 Part I Great Britain and the Empire in Europe, Second Edition. 0000
Billig's Philatelic Handbook, vol. 35, The Encyclopaedia of British Empire Postage Stamps 1661 - 1951, Vol. 1 Part II, Great Britain and the Empire in Europe, Second Edition. 0000
Billig's Philatelic Handbook, vol. 36, The Encyclopaedia of British Empire Postage Stamps 1806 - 1948, Vol. 2 Part I the Empire in Africa. 0000
Billig's Philatelic Handbook, vol. 37., The Encyclopaedia of British Empire Postage Stamps 1806 - 1948, Vol. 2 Part II the Empire in Africa. 0000
Billig's Philatelic Handbook, vol. 39, The Encyclopaedia of British Empire Postage Stamps 1775 - 1950, Vol. III The Empire in Asia, Part II, South Central Asia, India. 0000
Billig's Philatelic Handbook, vol. 40, The Encyclopaedia of British Empire Postage Stamps 1775 - 1950, Vol. III The Empire in Asia, Part III The Far East. 0000
Billig's Philatelic Handbook, vol. 41, The Encyclopaedia of British Empire Postage Stamps 1788 - 1952, Vol. IV The Empire in Australasia, Part 1, New South Wales, Queensland, South Australia, Tasmania. 0000
Billig's Philatelic Handbook, vol. 42, The Encyclopaedia of British Empire Postage Stamps 1788 - 1952, Vol. IV The Empire in Australasia, Part II, Victoria, Western Australia, The Commonwealth of Australia, British New Guinea and Papua, Nauru, Norfolk Island, Heard Island, Lord Howe Island, Macquarie Island, Thursday Island. 0000
Billig's Philatelic Handbook, vol. 43, The Encyclopaedia of British Empire Postage Stamps 1788 - 1952, Vol. IV The Empire in Australasia, Part III, New Zealand, Auckland Islands, Chatham Islands, Great Barrier Islands, Kermadec Islands, Antarctica- The Ross Depedency, Cook Islands, Samoa, Tokelau Islands, British Solomon Islands, Fiji, Gilbert and Ellice Islands, New Hebrides, Pitcairn Island, Tonga Islands. 0000