Thanks Pat! I see that I didn't express myself the way I really wanted
I've got most of Insulanders articles, but they mostly concern the Scandinavian two-wood bows, not these Siberian ones. I guess the construction is pretty much the same, but I'm sort of doing the same as Insulander - reconstructing the Scandinavian medieval two-wood bows, and I would like to use these Siberian bows as guidelines for the reconstruction of the Scandinavian medieval two-wood bows, which we just have fragments of. In other words, I need to go directly to the source of information on these Siberian ones.
Some good close-up photos would have been great, or a thorough study of their construction and geographical spread over the last thousand years