This is a list of external articles, published in various philatelic magazines. In the articles I wrote for my blog, I used some of below references for my research. Each article I write has the relevant references mentioned at the bottom of the article. When you see the blue color underlined text, you can click on there to get the full reference article. Agriculture tax related literature. Ref.1, Peter Iber, The King’s Monogram Essays, Thai Philately, January 1984, page 6-7