Where do you get all your material?

At stamp shows, this is a FAQ. The short answer is, All over the place. By way of an example, here's a true story:

At a London show some years ago, a dealer came up to my Stand, looked it over, and remarked, "You stock funny stuff. Are you interested in Ukraine? I've got a box in the office that's been there for years. It came from a good source. I could sell it to you if you're interested"

So I made a journey round the M25 and the box was placed in front of me. "Have you got a price?" I asked. The dealer had, in low four figures. Then I opened the box. Thousands of stamps in sheets, mostly common; thousands of stamps in glassines; odd bits of postal history; the auction catalogues which identified where the contents of this box came from. They were the unsolds and a big remainder Lot from the 1987 Swiss sale of the Vyroyyj collection.

Eugene Vyrovyj (1889 - 1945) was one of the great pre-1939 collectors of Ukrainian Tridents, especially the Tridents of Podilia. He won numerous medals for his Exhibit collection. He had links to the exile government of Ukraine, and this was probably the source of some of his material. Though he committed suicide in 1945, the collection did not come on the market until the 1987 Swiss sale, at which date I had not yet started dealing.

Yes, Reader, I bought the box.