The De La Rue Years 1878-1910, vol.1 and vol.2, by W. A. Wiseman
G.B. Departmental Stamps 1882-1914 by W. A. Wiseman
Great Britain Specialised Stamp Catalogue Volume 1: Queen Victoria (16th Edition), published by Stanley Gibbons, 2012
Postage Stamps of Great Britain: The Official Issues by Sotheby’s, July 1990
Great Britain November 2015 (pdf catalogue) by Stanley Gibbons
The GB Overprints Society
About: The GBOS helps members to explore the many ways and reasons why British stamps and other postal material have been overprinted, whether it is for use outside the UK or for special functions within the UK. They produce a journal four times a year, as well as holding collector presentations at shows such as Stampex.
Journal: The Overprinter
The Great Britain Philatelic Society
About: The GBPS helps members with all aspects of GB philately. They meet 8 times a year, usually in London, to hold special collector presentations as well as member competitions. They also produce a journal and a newsletter six times a year as well as publishing books.
Journal: The GB Journal