Reference 108, Phra U-Thaen, Symbol of the Thai Revenue Department.
Sales of Thomas De La Rue File Copies of Beverage and Tobacco Stamps.
The Waterlow Printed Revenue Stamps of Thailand 1887-1948.
Reference 107, Introduction to Early 1900's Stamp Printing Methods.
Thai Postmark Handbook, 1983-2017. Volume 7C, Edition 3, by Richard Blakeney.
Sales of De La Rue Specimen, Beverage and Tobacco stamps.
The Introduction of General Revenue Stamps in 1933.
Thai Government Post Offices, by Richard Blakeney.
Thai Postal Stationery and Booklet Catalog, Volume 6, Edition 10, by Richard Blakeney.
Thai Postmark Handbook, 1945-1982 Volume 7B, Edition 3, 2017. By Richard Blakeney.
Reference 51, History and Methods of Collecting Revenue Tax in Thailand.
Converting Dates from Thai Calendar to Christian Calendar.
Reference 105, Chirawit Theppornchai, Converting 'Krung Thep' CDS Cancels with Chula Sakarat Calendar Dates to Gregorian Calendar Dates
Thai Postmark Handbook, 1883-1945 Volume 7A, Third Edition, by Richard Blakeney.
Reference 52, The Introduction of General Revenue Stamps in 1933.
Thailand: The Definitive Stamps of H.M. King Bhumipol Adulyadej (Rama IX), Volume 8B, by Derek Bingham July 2017.
Collector: Peter Collins 192?-1991.
Peter Collins, Thailand, The Waterlow Proof Sheets 1917-1960.
Peter Collins collection?
Nararat Limnararat Large Gold Exhibit, Bangkok WSC 2023.