From SF Signal, which reports the that Dozois posted the following on his Facebook page:
My first two Best anthologies from St. Martin’s, THE YEAR’S BEST SCIENCE FICTION, FIRST ANNUAL COLLECTION and THE YEAR’S BEST SCIENCE FICTION, SECOND ANNUAL COLLECTION, are now available in Kindle editions. These are extremely hard editions to find in print, people have been asking me at cons for decades how they can find them, and I’ve seen them selling for hundreds and even thousands of dollars–so if you ever wanted to read them, the start of my long-running Best of the Year series (soon up to its Twenty-Ninth Annual Edition, which will out in July), this is probably your best chance.
You can find the First Annual Collection here and the Second Annual Collection here. They are only $7 each.
When I followed the first link, Amazon said “Not currently available”. It wasn’t the usual “p*ss off because you’re Australian” geolims message, so I’m not quite sure what this one implies.